Is the speed of light constant throughout the universe.?
Answer:
It is a basic postulate of the theory of relativity that the speed of light is constant. This can be broken down into two parts: The speed of light is independent of the motion of the observer. The speed of light does not vary with time or place.
Explanation:
The half-life of radium-226 is 1590 years. (a) A sample of radium-226 has a mass of 100 mg. Find a formula for the mass of the sample that remains after t years. (b) Find the mass after 1000 years correct to the nearest milligram. (c) When will the mass be reduced to 40 mg? SOLUTION (a) Let m(t) be the mass of radium-226 (in milligrams) that remains after t years. Then dm/dt = km and m(0) = 100, so this theorem gives m(t) = m(0)ekt = ekt. In order to determine the value of k, we use the fact that m(1590) = 1 2 . Thus e1590k = so e1590k = and 1590k = ln 1 2 = − ln(2) k = . Therefore m(t) = . We could use the fact that eln(2) = 2 to write the expression for m(t) in the alternative form m(t) = . (b) The mass after 1000 years is as follows. (Round your final answer to the nearest milligram.) m(1000) = ≈ mg
Answer:
See explanation
Explanation:
a) Formula for the mass of the sample that remains after t years = N= Noe^-kt
Where;
N = mass at time t years
No = mass at time t= 0
k = decay constant
t = time taken
So,
N = 100e^-kt
b) First,
t1/2 = -ln(1/2)/k
t1/2 = 0.693/k
t1/2 = half life of radium-226 =1590 years
1590 = 0.693/k
k = 0.693/1590
k = 4.36 * 10^-4
So,
N= 100e^-(4.36 * 10^-4 * 1000)
N= 65 mg
c) From
N = 100e^-kt
40 = 100e^-(4.36 * 10^-4t)
40/100 = e^-(4.36 * 10^-4t)
0.4 = e^-(4.36 * 10^-4t)
ln(0.4) = ln(e^-(4.36 * 10^-4t))
-0.9163 = -4.36 * 10^-4t
t = 0.9163/4.36 * 10^-4
t = 2102 years
How does the current in a series circuit compare
what is dimensional analysis
Answer:
The formula used to convert from the metric system outside of it. So like converting kilograms into pounds. The Formula is as follows:
# unit x (#unit/#unit) = # unit
^ ^ ^
I I I
given Conversion Answer
factor
*Note: Italic "units" are the same. Bold "units" are the same.
Example:
One thousand eighty kilometers is how many miles? Set it up dimensionally.
1080 km (1 mi/1.61 km) = 670.81 mi
*This is because 1080 x 1 = 1080, but then you divide 1080 by 1.61
A 50 kg mass is sitting on a frictionless surface. An unknown constant force called force A pushes the mass for 2 seconds until the mass reaches a velocity of 3 m/s. If the 50 kg mass is now pushed by an unknown force B and reaches the velocity of 3 m/s in 4 seconds, compare the impulse delivered to the mass when acted upon by force A with the impulse delivered to the mass when acted on by force B? *
A) The impulse delivered to the mass when acted upon by force A is greater
B) The impulse delivered to the mass when acted upon by force B is greater
C) The impulse is the same in each case
D) We need to know the value of force A and force B in order to determine this
Answer:
aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
An airplane has a momentum of 8.55 x 107 kg.m/s[S] and a velocity of 900 km/h[S]. Determine the mass of the airplane.
95000kg is the mass of the airplane.
What is momentum?A property of a moving body that the body has by virtue of its mass and motion and that is equal to the product of the body's mass and velocity.
It is also known as the property of a moving body that determines the length of time required to bring it to rest when under the action of a constant force.
Mathematically ,
p = mv
According to the question,
Momentum of airplane = 8.55 x 10⁷ kg.m/s
Velocity of airplane = 900 km/h
Computing the values in the formula,
p = mv
8.55 x 10⁷ kg.m/s = m x 900 km/h
m =[tex]\frac{8.55 * 10^7 kg.m/s}{900 km/h}[/tex]
m = 95000 kg
Therefore ,
The mass of the airplane 95000 kg
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A ball of mass m=10g, carrying a charge q =-20μe is suspended from a string of length L= 0.8m above a horizontal uniformly charged infinite plane sheet of charge density σ = 4μe/m^2. The ball is displaced from the vertical by an angle and allowed to swing from rest.
Required:
a. Obtain the equations of motion of the charged ball based on Newtonian laws of motion.
b. Assume the displaced angle θ is small and simplify the results obtained in part (a) to obtain the frequency of oscillations of the charged ball.
Answer:
a) [tex]- ( g - \frac{q}{m} \frac{\sigma }{ 2 \epsilon_o} ) \frac{sin \theta}{R }[/tex] = [tex]\frac{d^2 \theta}{d t^2}[/tex]
b) f = 2π [tex]\sqrt{ \frac{R}{ g - \frac{q}{m} \frac{\sigma }{2 \epsilon_o} } }[/tex]
Explanation:
a) To have the equations of motion, let's use Newton's second law.
Let's set a reference system where the x-axis is parallel to the path and the y-axis is in the direction of tension of the rope.
For this reference system the tension is in the direction of the y axis, we must decompose the weight and the electrical force.
Let's use trigonometry for the weight that is in the vertical direction down
sin θ = Wₓ / W
cos θ = W_y / w
Wₓ = W sin θ
W_y = W cos θ
we repeat for the electric force that is vertical upwards
F_{ex} = F_e sin θ
F_{ey} = F_e cos θ
the electric force is
F_e = q E
where the field created by an infinite plate is
E = [tex]\frac{ \sigma}{2 \epsilon_o}[/tex]
let's write Newton's second law
Y axis
T - W_y = 0
T = W cos θ
X axis
F_{ex} - Wₓ = m a (1)
we use that the acceleration is related to the position
a = dv / dt
v = dx / dt
where x is the displacement in the arc of the curve
substituting
a = d² x /dt²
we substitute in 1
q E sin θ - mg sin θ = m [tex]\frac{d^2 x}{dt^2}[/tex]
we have angular (tea) and linear (x) variables, if we remember that angles must be measured in radians
θ = x / R
x = R θ
we substitute
sin θ (q E - mg) = m \frac{d^2 R \ theta}{dt^2}
[tex]- ( g - \frac{q}{m} \frac{\sigma }{ 2 \epsilon_o} ) \frac{sin \theta}{R }[/tex] = [tex]\frac{d^2 \theta}{d t^2}[/tex]
this is the equation of motion of the system
b) for small oscillations
sin θ = θ
therefore the solution is simple harmonic
θ = θ₀ cos (wt + Ф)
if derived twice, we substitute
- ( g - \frac{q}{m} \frac{\sigma }{ 2 \epsilon_o} ) \frac{\theta}{R } θ₀ cos (wt + Ф) = -w² θ₀ cos (wt + Ф)
w² = [tex]\frac{g}{R}[/tex] - [tex]\frac{q}{m} \frac{ \sigma }{2 \epsilon_o} \frac{1}{R}[/tex]
angular velocity is related to frequency
w = 2π f
f = 2π / w
f = 2π/w
f = 2π [tex]\sqrt{ \frac{R}{ g - \frac{q}{m} \frac{\sigma }{2 \epsilon_o} } }[/tex]
why type of volcano is built almost entirely from ejected lava fragments
Answer:
Shield volcanoes
Explanation:
1. What is matter?
2. What are the three phases of matter?
3. Describe how gas particles move.
4. What is temperature?
5. The slower the particles, the ______________ the temperature.
6. A change in temperature causes what?
7. What is the difference between boiling and evaporation?
8. What is sublimation?
9. Name the three ways thermal energy is transferred.
10. Sunburn is an example of what?
11. Give an example of convection.
12. What is conduction?
13. What is the difference between conductors and insulators?
Answer:
1.matter is any substance that has mass and takes up space by having volume.
2.The three fundamental phases of matter are solid, liquid, and gas (vapour),
3.In gases the particles move rapidly in all directions, frequently colliding with each other and the side of the container. With an increase in temperature, the particles gain kinetic energy and move faster. ... In liquids, particles are quite close together and move with random motion throughout the container.
3.In gases the particles move rapidly in all directions, frequently colliding with each other and the side of the container. With an increase in temperature, the particles gain kinetic energy and move faster. ... In liquids, particles are quite close together and move with random motion throughout the container.
Define speed and what is it’s SI unit.
Find the current if 20C of charge pass a particular point in a circuit in 10 seconds.
Answer:
2 A
Explanation:
From the question,
Q = it..................... Equation 1
Where Q = Quantity of charge, i = cudrrent, t = time.
Make i the subject of the equation
i = Q/t.......................... Equation 2
Given: Q = 20 C, t = 10 seconds.
Substitute these values into equation equation 2
i = 20/10
i = 2 A.
Hence the current is 2A
Given values are:
Charge, Q = 20 CTime, t = 10 secondsAs we know,
→ [tex]Current = \frac{Charge}{Time}[/tex]
or,
→ [tex]i = \frac{Q}{t}[/tex]
BY substituting the values, we get
[tex]= \frac{20}{10}[/tex]
[tex]= 2 \ A[/tex]
Thus the answer above is right.
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When a rocket is 4 kilometers high, it is moving vertically upward at a speed of 400 kilometers per hour. At that instant, how fast is the angle of elevation of the rocket increasing, as seen by an observer on the ground 5 kilometers from the launching pad
Answer:
The angle of elevation of the rocket is increasing at a rate of 48.780º per second.
Explanation:
Geometrically speaking, the distance between the rocket and the observer ([tex]r[/tex]), measured in kilometers, can be represented by a right triangle:
[tex]r = \sqrt{x^{2}+y^{2}}[/tex] (1)
Where:
[tex]x[/tex] - Horizontal distance between the rocket and the observer, measured in kilometers.
[tex]y[/tex] - Vertical distance between the rocket and the observer, measured in kilometers.
The angle of elevation of the rocket ([tex]\theta[/tex]), measured in sexagesimal degrees, is defined by the following trigonometric relation:
[tex]\tan \theta = \frac{y}{x}[/tex] (2)
If we know that [tex]x = 5\,km[/tex], then the expression is:
[tex]\tan \theta = \frac{y}{5}[/tex]
And the rate of change of this angle is determined by derivatives:
[tex]\sec^{2}\theta \cdot \dot \theta = \frac{1}{5}\cdot \dot y[/tex]
[tex]\frac{\dot \theta}{\cos^{2}\theta} = \frac{\dot y}{5}[/tex]
[tex]\frac{\dot \theta\cdot (25+y^{2})}{25} = \frac{\dot y}{5}[/tex]
[tex]\dot \theta = \frac{5\cdot \dot y}{25+y^{2}}[/tex]
Where:
[tex]\dot \theta[/tex] - Rate of change of the angle of elevation, measured in sexagesimal degrees.
[tex]\dot y[/tex] - Vertical speed of the rocket, measured in kilometers per hour.
If we know that [tex]y = 4\,km[/tex] and [tex]\dot y = 400\,\frac{km}{h}[/tex], then the rate of change of the angle of elevation is:
[tex]\dot \theta = 48.780\,\frac{\circ}{s}[/tex]
The angle of elevation of the rocket is increasing at a rate of 48.780º per second.
A ray of light is incident on a plane mirror at an angle of 30 degree state the angle of reflection?
Answer:
30°
Explanation:
The law of reflection states that when a ray of light reflects off a surface, the angle of incidence is equal to the angle of reflection.
∠i = ∠r
so as ∠i = 30°
∠r will also be 30°
Which would be a good analogy of wave motion
Answer:
i believe it would be C
Explanation:
Which statement about oceans is incorrect?
A Evaporation occurs when water is warmed by the sun.
B Most evaporation and precipitation occur over the ocean.
C 97 percent of Earth's water is fresh water from the ocean.
D Water leaves the ocean by the process of evaporation.
When individuals improve their aerobic endurance, which body systems are affected?
When individuals improve their aerobic endurance, which body systems are affected?
Anwser: your heart and lungs
You push a 1.5 kg ball across a desk for 2 seconds, so that 10 J of work have been done. How much power was produced?
Answer
Answer:
i need help with the same question
Explanation:
Each vertical line on the graph is 1 millisecond (0.001 s) of time. What is the period and
frequency of the sound waves?
Help me!!!!!
Answer:
1000 Hz
Explanation:
please mark me as brainliest
Which of the following statements about treatment for self-injury (SI) is not true?
Answer:
Its true
Explanation:
What is the weight of a 25 kg object on Earth with an acceleration due to gravity of 9.8m/s/s?
2.45 n
24.5 n
245 n
2450 n
A truck of mass 1600 kg is traveling at 15 m/s. In order to avoid running over a squirrel in the middle of the road, the truck driver begins to brake. What must the braking force on the truck be if the truck comes to stop in 2 s? *
a)12000n
b) 8000n
c)7000n
d)6000n
1. Odysseus traveled from Troy to Ithaca. What
was the acceleration of Odysseus' ship if its mass
was 900,000 kg and it moves across the water with
a force of 300,000 N?
Answer: 0.33 m/s^2
Explanation:
The acceleration of Odysseus' ship as it moves across the water from Troy to Ithaca is 0.33m/s²
Given the data in the question;
Mass of Odysseus' ship; [tex]m= 900000kg[/tex]Force with which Odysseus' ship moves across the water; [tex]F = 300000N[/tex]Acceleration; [tex]a = ?[/tex]To determine the acceleration of the ship, We the equation from Newton's Second Law of Motion:
[tex]F = m\ *\ a[/tex]
Where F is the force, m is the mass and a is the acceleration
Lets make acceleration ''a'', the subject of the formula
[tex]a = \frac{F}{m}[/tex]
Now, we substitute our given values into the equation
[tex]a = \frac{300000N}{900000kg}[/tex]
We know that, A newton is defined as [tex]1 kg.m/s^2[/tex]
[tex]a = \frac{300000 kg.m/s^2}{900000kg} \\\\a = 0.33m/s^2[/tex]
Therefore, the acceleration of Odysseus' ship as it moves across the water from Troy to Ithaca is 0.33m/s²
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what is impulse in physical science
Answer:
In classical mechanics, impulse (symbolized by J or Imp) is the integral of a force, F, over the time interval, t, for which it acts. Since force is a vector quantity, impulse is also a vector quantity. ... A resultant force causes acceleration and a change in the velocity of the body for as long as it acts.
8. What is the mass of a toy car with a speed of 12.5 m/s and 47500 J of kinetic energy?
Answer:
608kg
Explanation:
Formula : Kinetic energy
½ ×mass x speed²
47500
½×12.5²
=608 Kg
What is the difference in the speed of the generator with a small magnet and a generator with a large magnet?
Answer:
uADHTiszA?kv
Explanation:
PLS HELP
SHOW WORK
A car starting from rest accelerates at a rate of 1.5 m/s ^ 2 What is its final speed at the end of 18.0 seconds ?
Answer:
27 ms^-1
Explanation:
by using v= u + at
u = 0 ( because the object id starting from rest)
v= 0 + 1.5 x 18
v = 27 ms^-1
Who watching all star draft? Luka better get picked first ong
In what way does water change when condensation occurs?
from gas to liquid
from liquid to solid
from liquid to gals
from solid to liquid
an egg is Free Falling Down from a nest in a tree (neglect air resistance)
We are to calculate the acceleration.
Answer:
-9.8 m/s²
Explanation:
Since the egg is in a free fall, it means that the force due to gravity will be equal to the normal force.
Now,
Force due to gravity: F_g = mg
Normal force; F_n = ma
Thus;
mg = ma
m will cancel out to get
g = a
Since it is a free fall motion, then gravity is negative;
-g = a
g has a constant value of 9.8 m/s². Thus;
a = -9.8 m/s²
a sentence that describes how energy is related to work
Answer:
Energy should be transferred to an object in order to move it. ... This amount of energy transferred by the force to move an object is called work or work done. Thus, the relation between Work and Energy is direct. That is, the difference in the Kinetic energy of an object is work done by an object