In deep water, a tsunami moves very fast and has a long wavelength and a small amplitude (see A in picture). As it enters shallower water, it slows down, and the wavelength decreases. This causes the wave to become much taller (see B in picture).As waves slow down, they start to bunch together, so they have a shorter wavelength than before. This can also be explained by the wave equation v = f x λ (speed = frequency x wavelength), which shows that, when a wave’s speed decreases, it must have a shorter wavelength than before – slowing down won’t change the wave’s frequency.Having a shorter wavelength means that the waves get higher. You could think of the shortened wave as being ‘squashed’ sideways – the water in the wave has to get higher because there’s not as much room for it within the shorter wavelength. It’s a bit like squeezing a toothpaste tube – all the toothpaste is forced upwards.
Answers
Given:
The wavelength of the wave decreases as it gets closer to the shore.
The speed of the wave decreases as it gets closer to the shore.
The waves get taller as it gets closer to the shore.
To find:
How does a change in velocity cause a change in amplitude?
Explanation:
The amplitude of a wave is described as the distance of the highest point of vibration or the oscillation of the wave from its mean position.
Given that as the velocity of the speed decreases the waves get taller. That is as the velocity decreases the distance of the highest point of vibration of the wave from its equilibrium or mean position increases.
Final answer:
Thus as the velocity of the wave decreases, its amplitude increases.
Related Questions
The once-popular LP (long-play) records were 12 in. in diameter and turned at a constant 33 1/3 rpm.
Answers
The angular speed of the long-play (LP) in rad/s is 3.49rads/s and its period in seconds is 1.80 seconds.
How is angular speed and period calculated?To convert the angular speed from revolution per minutes (rpm) to seconds the following formula is used:
ω = (k revolution/60 seconds) x (2π/1 revolution)
ω = 2πk/60seconds (k x 2π/T in seconds)
where, k = constant in rpm, 33 1/3rpm = 33.3333rpm
ω = 2π33.3333/60 = 209.4374/60
ω = 3.49rad/s
For period in seconds, ω = 2π/T
where, T = period and ω = angular speed, 3.49rad/s
To find T, T = 2π/ω
T = 2π/3.49rad/s
T = 1.80s
Using the formula, ω = 2πk/60seconds, the angular speed in rad/s of the LP is 3.49rad/s and the time period for the records using T = 2π/ω is 1.80s.
The full question is:
The once-popular LP (long-play) records were 12 inches in diameter and turned at a constant 33(1/3) rpm. Find the angular speed of the LP in rad/s and its period in seconds.
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Even when the head is held erect, as in the figure below, its center of mass is not directly over the principal point of support (the atlanto-occipital joint). The muscles in the back of the neck musttherefore exert a force to keep it erect. That is why your head falls forward when you fall asleep in class. If the perpendicular distance between the line of action for the weight of the head and thepivot point is rw = 2.4 cm and the perpendicular distance between the line of action for theforce the muscles exert on the head and the pivot point is rMi=5.1 cm. determine each or thefollowina. (Assume the weight of the head is 50 N.)
Answers
We are asked to determine the force required by the neck muscle in order to keep the head in equilibrium. To do that we will add the torques produced by the muscle force and the weight of the head. We will use torque in the clockwise direction to be negative, therefore, we have:
[tex]\Sigma T=r_{M\perp}(F_M)-r_{W\perp}(W)[/tex]Since we want to determine the forces when the system is at equilibrium this means that the total sum of torque is zero:
[tex]r_{M\perp}(F_M)-r_{W\perp}(W)=0[/tex]Now, we solve for the force of the muscle. First, we add the torque of the weight to both sides:
[tex]r_{M\perp}(F_M)=r_{W\perp}(W)[/tex]Now, we divide by the distance of the muscle:
[tex](F_M)=\frac{r_{W\perp}(W)}{r_{M\perp}}[/tex]Now, we substitute the values:
[tex]F_M=\frac{(2.4cm)(50N)}{5.1cm}[/tex]Now, we solve the operations:
[tex]F_M=23.53N[/tex]Therefore, the force exerted by the muscles is 23.53 Newtons.
Part B. To determine the force on the pivot we will add the forces we add the vertical forces:
[tex]\Sigma F_v=F_j-F_M-W[/tex]Since there is no vertical movement the sum of vertical forces is zero:
[tex]F_j-F_M-W=0[/tex]Now, we add the force of the muscle and the weight to both sides to solve for the force on the pivot:
[tex]F_j=F_M+W[/tex]Now, we plug in the values:
[tex]F_j=23.53N+50N[/tex]Solving the operations:
[tex]F_j=73.53N[/tex]Therefore, the force is 73.53 Newtons.
ulietta and Jackson are playing miniature golf. Julietta's ball rolls into a long, straight upward incline with a speed of 3.24 m/s and accelerates at -0.234 m/s/s for 2.56 seconds until it reaches the top of the incline and then continues along an elevated section. Determine the length of the incline?
Answers
The distance that is covered by the ball is 22.4 m.
What is the length of the incline?We know that the length of the incline is the distance that have been travelled by the ball as it rolls up the incline. We have to use the formula for motion which is;
v^2 = u^2 + 2as
v = final velocity
u = initial velocity
a = acceleration
s = distance
Now;
3.24^2 = 0^2 - 2(-0.234) * s
3.24^2 = - 2(-0.234) * s
s = 3.24^2/- 2(-0.234)
s = 22.4 m
Thus the ball would roll up a distance of about 22.4 m.
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Questions : 1. What is the penguin’s average velocity during the chase? 2. What is the penguin’s average speed during the chase?
Answers
Given:
• Distance traveled rightward = 6 m
,• Distance traveled leftward = 10 m
,• Total time, t = 30 s
Let's solve for the following:
• (1). What is the penguin’s average velocity during the chase?
To find the average velocity, apply the formula:
[tex]v=\frac{d}{t}[/tex]Where:
• v is the average velocity in m/s
,• d is the displacement
,• t is the total time in seconds.
The displacement given a 6 meters rightward move and 10 m leftward move is:
d = 6m + (-10 m) = 6m - 10m = -4 m
Thus, we have:
[tex]\begin{gathered} v=\frac{-4}{30} \\ \\ v=-0.13\text{m/s} \end{gathered}[/tex]The average velocity is -0.13 m/s.
• (2). What is the penguin’s average speed during the chase?
To find the average speed, we have:
[tex]v=\frac{d}{t}[/tex]v is the average speed in m/s
d is the total distance = 6m + 10m = 16m
t is the total time = 30 s
Thus, we have:
[tex]\begin{gathered} v=\frac{16}{30} \\ \\ v=0.53\text{ m/s} \end{gathered}[/tex]The average speed is 0.53 m/s.
ANSWER:
0. Average velocity = -0.13 m/s
,1. Average speed = 0.53 m/s
A truck is driving 500 meters/minute. He slows down to a complete stop over 0.25minutes. Calculate his acceleration.
Answers
Given
The velocity is v=500 meters/minute
The time taken is t=0.25 minute
To find
The acceleration
Explanation
We know,
The acceleration is the ratio of velocity to time.
Thus,
[tex]\begin{gathered} a=\frac{v}{t} \\ \Rightarrow a=\frac{500}{0.25} \\ \Rightarrow a=2000\text{ m/min}^2 \end{gathered}[/tex]Conclusion
The acceleration is
[tex]2000\text{ m/min}^2[/tex]How much heat is necessary to change 500 g of ice at - 10°C to water at 20°C ?
Answers
Apply the specific heat equation:
q= mcΔT
q= heat energy
m= mass = 500g
c = specific heat capacity = 4.186 J/gC
ΔT= change in temperature = 30°
q= 500g x 4.186 J/gC x 30 C = 62,790 Joules
Then apply the latent heat formula:
q= mL
L = latent heat fusion, vaporization, etc for the substance = 334 J/g
q = 500 x 334 J/g = 167,000 J
Total q = 62,790 + 167,000 = 229,790 J
One end of a thin rod is attached to a pivot about which it can rotate without friction. Air resistance is absent. The rod has a length of 0.48 m and is uniform. It is hanging vertically straight downward. The end of the rod nearest the floor is given a linear speed V so that the rod begins to rotate upward about the pivot. What must be the value of V such that the rod comes to a momentary halt in a straight up orientation, exactly opposite to its initial orientation?
Answers
ANSWER:
5.32 m/s
STEP-BY-STEP EXPLANATION:
We can determine the velocity from the following equation (initial kinetic energy:
[tex]\frac{1}{6}\cdot v^2_0=g\cdot L[/tex]Where L is the length of the rod and g would be gravity, we replace and calculate the value of the initial velocity:
[tex]\begin{gathered} v^2_0=6\cdot9.81\cdot0.48 \\ v^{}_0=\sqrt[]{28.2528} \\ v_0=5.32\text{ m/s} \end{gathered}[/tex]The velocity is 5.32 m/s
How many kilocalories must be removed from 920 grams of water at a temperature of zero degrees Celsius to transform it into ice at zero degrees Celsius? A)2760 B)497000 C)73.3
Answers
Given:
The mass of the water, m=920 g
The temperature of the water, T=0 °C
To find:
The heat required to be removed to transform water to ice.
Explanation:
The latent heat of the fusion of ice is L=79.7 Cal/g.
The latent heat of fusion is the heat that is needed to be removed from the water to convert it into ice.
The amount of the heat that is needed to be removed is given by,
[tex]Q=mL[/tex]On substituting the known values,
[tex]\begin{gathered} Q=920\times79.7 \\ =73324\text{ Cal} \\ \approx73.3\text{ kCal} \end{gathered}[/tex]Final answer:
The amount of heat that is to be removed to convert the given amount of water into ice is 73.3 kCal.
Therefore the correct answer is option C.
18.
An object with a mass of 3.2 kg has a force
What is the resulting acceleration of the object?
of 7.3 newtons
applied to it.
Answers
2.28125 ms^-2 is the resulting acceleration of the object.
Force = ma
a=F/m
a=7.3 newtons/ 3.2 kg
a=2.28125 ms^-2
Acceleration is the rate of change in a moving object's speed and direction over time. When anything moves faster or slower, it is considered to be accelerating. Motion on a circle increases even while the speed is constant because the direction is always changing.
Since acceleration has both a magnitude and a direction, it is a vector quantity. Velocity is a vector quantity as well. The definition of acceleration is the change in velocity vector during a time interval divided by the time interval.
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A 45.8 kg block is placed on an inclined plane that is 44.2 degrees from the horizontal. What is the acceleration of the block? Ignore friction.I have to do the following:1. Draw a free body diagram2.Identify Givens and Unknowns3.Identify the Equations4.Set up the equation using the givens and unknowns5.Solve
Answers
The acceleration of the block = 6.83 m/s²
Explanation:The free body diagram representing the given description is:
The mass of the block, m = 45.8 kg
The angle of inclination, θ = 44.2°
Acceleration due to gravity, g = 9.8 m/s²
Applying Newton's second law of motion
∑F = ma
mgsinθ = ma
Divide both sides by m
[tex]\begin{gathered} \frac{mg\sin \theta}{m}=\text{ }\frac{ma}{m} \\ a\text{ = gsin}\theta \end{gathered}[/tex]a = 9.8 sin (44.2)
a = 9.8(0.697)
a = 6.83 m/s²
A rocket in outer space is traveling toward a far-off planet. An astronaut turns on the rocket’s engines, which exerts a force on the rocket. There is no gravity or air resistance.When the astronaut turns off the engines, what will the rocket do?possible answersIt will steadily slow down because no forces are acting on it.It will continue moving with a constant speed because no forces are acting on it.It will continue moving with a constant speed because the force from the engines is still acting on it.It will steadily slow down until the force from the engines is gone.
Answers
Answer:
It will continue moving at a constant speed because no forces are acting on it.
Explanation:
By the second law of Newton, the force is proportional to the acceleration. If there is no force, there is no acceleration. So, when the astronaut turns off the engines, the rocket will have no acceleration which means that the speed will be constant.
Therefore, the answer is:
It will continue moving at a constant speed because no forces are acting on it.
URGENT!! ILL GIVE
BRAINLIEST!!!! AND 100 POINTS!!!!!!
Answers
Property that makes cup and spoon get hot is, (C) Heat was convicted to the cup and spoon where the hot water molecules moved through the cooler molecules in the surrounding and transferred the heat.
What is heat?Heat is a physical property that means when an object is collected into the fire it can absorb some energy through the fire. That energy is called heat. It can be measured by °c.
How can we conclude the statement about heat?Heat is a property that transfers its energy into a cooler object to maintain equilibrium. When the chocolate object and hot water were poured into a ceramic cup it start transferring the heat.
As we know ceramic is heat conducting particle. It can be absorb the heat and transferred it too. So when the hot water is poured in there, the heat has connection with the cold ceramic cup and spoon.
Then the heat started to transfer his heat into the cold ceramic cup and spoon to maintain the energy. The ceramic cup and spoon started to collect the heat within them.
For this reason, Priya's cup and spoon become hot. So from this discussion we can conclude that,
The Heat was convicted to the cup and spoon where the hot water molecules moved through the cooler molecules in the surrounding and transferred the heat.
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Answer: (C) Heat was convicted to the cup and spoon where the hot water molecules moved through the cooler molecules in the surrounding and transferred the heat.
hi good afternoon pls I need solution to a problem the question goes like this : The horizontal floor of a water reservoir is said to be 1.0m deep when viewed vertically from above .if the refractive index of water is 1.35 calculate the real depth of the reservoir a)2.35mb)1.35mc)1.00md)0.35m
Answers
First, you have to use Snell's law to calculate the refractive angle. Remember the light enters at a 90 angle and the refractive index of air is 1.
[tex]\begin{gathered} h\cdot sin\theta2=1m \\ h=\frac{1}{sin(47.79)}=1.35m \end{gathered}[/tex]A rectangular painting is 120 cm wide and 80 cm high. At what speed must the painting move parallel to its width if it is to appear to be square?
Answers
Given
A rectangular painting is 120 cm wide and 80 cm high.
To find
At what speed must the painting move parallel to its width if it is to appear to be square?
Explanation
According to length contraction, the proper length of an object contracts when it moves with a velocity.
Thus,
[tex]\begin{gathered} l=l_o\sqrt{1-\frac{v^2}{c^2}} \\ \Rightarrow80=120\sqrt{1-\frac{v^2}{c^2}} \\ \Rightarrow\frac{2}{3}=\sqrt{1-\frac{v^2}{c^2}} \\ \Rightarrow\frac{4}{9}=1-\frac{v^2}{c^2} \\ \Rightarrow\frac{v^2}{c^2}=1-\frac{4}{9} \\ \Rightarrow\frac{v^2}{c^2}=\frac{5}{9} \\ \Rightarrow v=\frac{\sqrt{5}}{3}c \end{gathered}[/tex]Conclusion:
The required velocity is
[tex]\frac{\sqrt{5}c}{3}\frac{m}{s}[/tex]Current is measured through a resistor during a laboratory experiment. 1.833 C of charge is measured to pass through the resistor in 1,538 s. What is the current of the circuit? (6 decimal places)
Answers
Given,
The charge passed through the resistor, q=1.833 C
The time, t=1,538 s
The electric current can be defined as the time rate of flow of charge. Thus the electric current that passes through the resistor is given by,
[tex]I=\frac{q}{t}[/tex]On substituting the known values,
[tex]\begin{gathered} I=\frac{1.833}{1538} \\ =1.191807\times10^{-3}\text{ A} \\ =1.191807\text{ mA} \end{gathered}[/tex]Thus the current of the circuit is 1.191807 mA.
Determine the mass of an object when the period of oscillation is 11 s and spring constant is 10 N/m.
Answers
Answer:
30.65 Kg.
Explanation:
The period of oscillation T, the spring constant k, and the mass m are related by the following equation.
[tex]T=2\pi\sqrt[]{\frac{m}{k}}[/tex]So, solving for m, we get:
[tex]\begin{gathered} \frac{T}{2\pi}=\sqrt[]{\frac{m}{k}} \\ \frac{T^2}{4\pi^2}=\frac{m}{k} \\ \frac{T^2k}{4\pi^2}=m \\ m=\frac{T^2k}{4\pi^2} \end{gathered}[/tex]Therefore, replacing T = 11 s and k = 10 N/m, we get:
[tex]m=\frac{(11s)^2(10\text{ N/m)}}{4\pi^2}=30.65\text{ kg}[/tex]Then, the mass of the object is 30.65 Kg.
A sample of gas in a cylinder is compressed by a piston at a constant pressure of 0.800 atm. The volume of the cylinder decreases from 8.50 L to 2.00 L, while at the same time 320 J of energy leaves the gas by heat.
(a)
What is the work done on the gas (in J)?
Answers
The work done on the gas 526.89 Joule.
What is work done?The amount of force multiplied by the distance the thing travelled in the direction of the applied force is how much work is done on an object.
Work is equal to force times distance.
Given parameters:
Constant pressure of the gas: p = 0.800 atm.
Initial volume of the cylinder: V₁ = 8.50 L.
Final volume of the cylinder: V₂ = 2.00 L.
Energy leaves the gas by heat: E = 320 J.
So, the work done by the gas (W) = pΔV = p(V₂ - V₁)
= 0.800(2.00 - 8.50) atm-lit
= - 5.2 atm-lit
= - 5.2×101.325 Joule
= - 526.89 Joule.
Hence, The work done on the gas 526.89 Joule.
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Use Polya's four-step problem-solving strategy to solve the following exercise.A frog is at the bottom of a 13-foot well. Each time the frog leaps, it moves up 3 feet. If the frog has not reached the top of the well, then the frog slides back 1 foot before it is ready to make another leap. How many leaps will the frog need to escape the well?______ leaps
Answers
ANSWER:
6 leaps
STEP-BY-STEP EXPLANATION:
Keep adding 2 until the sum is 10 and count the number of 2 that has been added. Then add 1 to that number, as the last jump will cover the remaining 3 feet and the frog will reach the top of the well.
[tex]\begin{gathered} 2+2+2+2+2=10 \\ 5\text{ leaps} \end{gathered}[/tex]Carry out the plan
The number of 2 added is 5.
Add 1 to the number 5.
5+1 = 6
Hence, the total number of leaps is 7.
For 1st leap
3- 1 = 2
For 2nd leap
2+3 = 5-1 = 4
For 3rd leap
4+3=7-1 = 6
For 4th leap
6+3=9-1 = 8
For 5th leap
8+3=11-1=10
For 6th leap
10+3 = 13
Hence, the total number of leaps is 6
With what force (per hand) does a man need to lift to keep the wheelbarrow in balance?The total weight of the cart and the load is 100 kg and at the point shown in the center of gravityAnd the right answer about this is 12.5kg per hand
Answers
ANSWER
122.5N per hand
EXPLANATION
First, we have to draw a free body diagram,
A wheelbarrow is an example of a lever but in this case, both forces are on the same side of the pivot - which is the wheel. To keep the wheelbarrow in balance, the output force, Fo, must be equal to the weight of the wheelbarrow,
[tex]F_o=m\cdot g=100\operatorname{kg}\cdot9.8m/s^2=980N[/tex]Using the mechanical advantage relation between the input and output forces and the lever arms,
[tex]\frac{F_o}{F_i}=\frac{l_i}{l_o}_{}[/tex]We have to find Fi. To solve for Fi, first raise both sides to the exponent of -1 - in other words, flip both fractions,
[tex]\frac{F_i}{F_o}=\frac{l_o}{l_i}[/tex]And multiply both sides by Fo,
[tex]F_i=F_o\cdot\frac{l_o}{l_i}[/tex]The output force is the one found before, 980N. Then, the length of the lever arm of the output force is the distance from the center of gravity to the wheel, 0.5m, and the length of the lever arm of the input force is the distance from the man's hands to the wheel, 2m,
[tex]F_i=980N\cdot\frac{0.5m}{2m}=\frac{980N}{4}=245N[/tex]The total force the man has to make is 245N. Assuming each hand can support the same weight, then each hand should be doing 122.5N of force to keep the wheelbarrow in balance.
Which of the following best describes refraction of a wave?A. As a wave moves around a corner or through an opening, itsdirection of motion changes.B. As a wave reaches the interface between two different media, itsdirection of motion changes and it remains in the first medium.C. As a wave moves from one medium to another, the energy of thewave is converted to other forms of energy.O D. As a wave moves from one medium into another in which itsspeed is different, the wave changes direction.
Answers
From the given answer choices, let's select the best statement that best describes refraction of a wave.
Refraction of a wave can be said to be a change in direction of waves when they move from one medium to another.
As wave move from
2. One of your classmates, in a fit of unrestrained ego, jumps onto a lab table!a) Draw a qualitative force diagram for the table. Use marks on the vectors to show the balance of forces.b) Your classmate's mass is 65 kg and the table weighs 500 N. Calculate the normal force on thetable by the floor. Show your work!c) Find the mass of the table.
Answers
a)
b)
Apply newton's second law
N = Wm + Wt
N = normal
Wm = weight of the man = mass of classmate *gravity= 65 kg * 9.8 m/s = 637 N
Wt = weight of the table = 500 N
N = 637 + 500 = 1,137 N
c) Weight = mass x gravity
Mass = Weight / gravity = 500 N / 9.8 m/s^2 = 51.02 kg
A 0.09 kg beetle climbs vertically a distance of 0.35 m up a wall at a speed of 0.02 m/s. What is the beetle’s power output?
Answers
The power output of the beetle of mass 0.09 kg is 0.0176 W.
What is power?Power is the rate at which work is done per seconds
To calculate the power output of the beetle, we use the formula below.
Formula:
P = mgv............. Equation 1Where:
P = Power output of the beetlem = Mass of the beetlev = Velocity of the beetleg = Acceleration due to gravityFrom the question,
Given:
m = 0.09 kgg = 9.8 m/s²v = 0.02 m/sSubstitute these values into equation 1
P = 0.09×9.8×0.02P = 0.0176 W.Hence, the beetle's power output is 0.0176 W.
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An atom of carbon-14 isotope has more protons than an atom of carbon-12 isotope. Is this true or false?
Answers
Carbon-12 and carbon-14 are isotopes of each other. Isotopes are the elements that contain the same number of protons but a different number of neutrons.
CArbon-12 contains six protons and six neutrons. While carbon-14 contains six protons and eight neutrons.
Thus the given statement is false.
A person with a mass of 78.0 kg is standing on a bathroom scale in an elevator that is accelerating downwards at a rate of 1.25 m/s2What is the normal force? (the reading on the scale)(input your answer with one decimal place)
Answers
Given:
• Mass, m = 78.0 kg
,• Acceleration = 1.25 m/s²
Let's find the normal force.
To find the normal force, apply the formula for Newton's second law:
[tex]\begin{gathered} \Sigma F_y=ma_y \\ \\ F-mg=-ma \end{gathered}[/tex]Where:
m is the mass of the person = 78.0 kg
a is the acceleration = 1.25 m/s²
g is acceleration due to gravity = 9.8 m/s²
F is the normal force
Thus, we have:
[tex]\begin{gathered} F=mg-ma \\ \\ F=m(g-a) \\ \\ F=78(9.8-1.25) \end{gathered}[/tex]Solving further:
[tex]\begin{gathered} F=78(8.55) \\ \\ F=666.9\text{ N} \end{gathered}[/tex]The reading on the scale will be in kilograms.
Hence, we have:
[tex]m=\frac{N}{g}=\frac{666.9}{9.8}=68.1\text{ kg}[/tex]Therefore, the reading on the scale will be 68.1 kg or 666.9 N
ANSWER:
666.9 N
What is the magnitude of a force that is required to keep a spring with a spring constant 205 N/m compressed 0.4 m from its starting point?
Answers
By Hooke's law we have that the magnitude of the force exerted by a pricng is given by:
[tex]F=kx[/tex]where k is the spring constant and x is the length of extension or compression, then we have:
[tex]F=205\cdot0.4=82[/tex]Therefore the force is 82 N
11 When early humans discovered fire, it likely changed the way they survived in harsh winter climates. What is another change that happened around the same time because of this discovery? A. Their diets moved from nuts and berries to include meat. B. They developed salves or ointments to deal with burns. C. Their language skills progressed to describe things like fire. D. They learned how to preserve food through fermentation.
Answers
Another change that happened around the same time as discovery of fire was that their diets moved from nuts and berries to include meat. So, the correct option is (A)
What was the influence of Fire on Human Evolution?Humans must have learned to handle fire very early in human history. Most likely due to natural sources such as lightning strikes and naturally occurring forest fires. It wasn't until much later that mankind invented how to make fire. Hominidae (genus Homo) appeared in East Africa about 2.5 million years ago, and fire is closely associated with many stages of evolution. The ability to cook food is thought to have led to the rise of Homo erectus from its more primitive ancestors.
Cooked foods provide much more energy than raw foods with low food consumption. This may have given time to develop social skills too. Cooked foods also detoxify potentially harmful bacteria. This has increased the variety of food available.
Cooking with fire is thought to have developed a large brain. These factors are thought to have driven the evolution of other human traits, including large brains and bodies, small teeth, modern limb proportions, and many social aspects of human-related behavior ( Wrangham et al. 1999). Indeed, by softening food, fire may have had a significant impact on extending human life beyond the age of healthy teeth.
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A water heater uses a resistor of 16 Ω to boil water. The heater is connected to a 240 V power source. If the heater is used for 2 hours a day, calculate the cost to run the heater for a year (365 days). The electricity cost by TNB is given as 21.8 sen/kWh.
Answers
First, calculate the power used each day. Use the following formula:
[tex]P=\frac{V^2}{R}[/tex]where,
V: voltage = 240V
R: resistor = 16 Ω
Replace the previous values into the formula for P:
[tex]P=\frac{(240V)^2}{16\Omega}=3600W=3.6kW[/tex]Then, consider that the energy used in kWh, each day, is:
[tex]E=P\cdot t=3.6kW\cdot2h=7.2\text{kWh}[/tex]And in a year, the energy used is:
[tex]E^{\prime}=7.2\text{kWh}\cdot365=2628kWh[/tex]And the cost will be:
[tex]\text{cost}=(2628kWh)(\frac{21.8sen}{\text{kWh}})=57290.4sen[/tex]Hence, the cost to run the heater in one year is 57290.4sen
A typical adult ear has a surface area of 2.61× 10-3 m². The sound intensity during a normal conversation is about 2.65 x 10-6 W/m² at the listener's ear. Assume that the sound strikes the surface of the ear perpendicularly. How much power is intercepted by the ear?
Answers
ANSWER:
6.9 x 10^-9 W
STEP-BY-STEP EXPLANATION:
Given:
Area (A) = 2.61× 10^-3 m²
Intensity (I) = 2.65 x 10^-6 W/m²
We can determine the power by the following formula:
[tex]\begin{gathered} P=A\cdot I \\ \\ \text{ We replacing:} \\ \\ P=2.61\cdot10^{-3}\cdot2.65\cdot10^{-6} \\ \\ P=6.9\cdot10^{-9}\text{ W} \end{gathered}[/tex]The power is 6.9 x 10^-9 W
Determine the order of magnitude of the following small number by entering the appropriate exponent n below: 4,870×1021kg≈10nkg .
Answers
We can see that the order of magnitude of the problem is:
[tex]n=21[/tex]Light from red, green and blue spotlights shine on asheet of paper. The paper contains cyan pigment. Whichof the three primary light colors will be absorbed by thepigment?
Answers
Given data:
The given colors are red, green, and blue.
The cyan pigment is capable of absorbing red color. The
The correct answer is red light.