Answer:
why does anyone need to know
Explanation:
1 plus one = 69
As a sports car travels along a level stretch of road with constant speed, most of the power developed by the engine is used to compensate for the energy transformations due to friction forces exerted on the sports car by the air and the road. If the power developed by the engine is 0.824 hp, calculate the total friction force acting on the sports car (in N) when it is moving at a speed of 30 m/s. One horsepower equals 746 W.
Answer:
20.49 N
Explanation:
From the question given above, the following data were obtained:
Power (P) = 0.824 hp
Velocity (v) = 30 m/s
1 h = 746 W
Force (F) =?
Next, we shall convert 0.824 hp to Watts (W). This can be obtained as follow:
1 h = 746 W
Therefore,
0.824 hp = 0.824 hp × 746 W / 1 h
0.824 hp = 614.704 W
Finally, we shall determine the force as follow:
Power (P) = 614.704 W
Velocity (v) = 30 m/s
Force (F) =?
P = F × v
614.704 = F × 30
Divide both side by 30
F = 614.704 / 30
F = 20.49 N
3. A woman drove her car from home to her daughter's school. The odometre on her dashboard says she travelled 4.5 km to do this. She then immediately drove back home, using a different route, which was 5.5 km long. The whole journey took 30 minutes.
a. What distance did she travel?
b. What was her displacement?
C. What was her average speed during the journey?
Answer:
Look Below -->
Explanation:
a. She traveled 10 km, add 4.5 km + 5.5 km = 10 km (Distance is the total units travelled, so just add them all up :) )
b. Her displacement is 0 km because she went back home. (Displacement is the difference between the end and starting points)
c. 3 km/hr (30 minutes / 10 km)
In a mass spectrometer, a specific velocity can be selected from a distribution by injecting charged particles between a set of plates with a constant electric field between them and a magnetic field across them (perpendicular to the direction of particle travel). If the fields are tuned exactly right, only particles of a specific velocity will pass through this region undeflected. Consider such a velocity selector in a mass spectrometer with a 0.105 T magnetic field.
Part (a) What electric field strength, in volts per meter, is needed to select a speed of 3.8 × 106 m/s?
Part (b) What is the voltage, in kilovolts, between the plates if they are separated by 0.75 cm?
Answer:
a).[tex]$3.99 \times 10^5 \ v/m$[/tex]
b). 2.9925 kV
Explanation:
Given :
For mass spectrometer
The magnetic field = B
B = 0.105 T
a). Given speed, v = [tex]$3.8 \times 10^6 \ m/s$[/tex]
We known
[tex]$\frac{E}{B}=v$[/tex]
∴ [tex]$E= 3.8 \times 10^6 \times 0.105$[/tex]
[tex]$=3.99 \times 10^5 \ v/m$[/tex]
b). Now spectrometer, d = 0.75 cm
[tex]$d=0.75 \times 10^{-2} \ m$[/tex]
We known
[tex]$E=\frac{V}{d}$[/tex]
[tex]$V = E\times d$[/tex]
[tex]$V = 3.99 \times 10^5 \times 0.75 \times 10^{-2}$[/tex]
[tex]$V = 2.9925 \times 10^3 \ V$[/tex]
= 2.9925 kV
what is the acceleration of an object that has a velocity of 25.0m/s and is moving in a circle of a radius of 10.0 m?
Answer:
[tex]a=62.5\ m/s^2[/tex]
Explanation:
Given that,
The velocity of the object, v = 25 m/s
Radius of the circle, r = 10 m
We need to find the acceleration of the object. The centripetal acceleration act on it. It is given by :
[tex]a=\dfrac{v^2}{r}\\\\a=\dfrac{(25)^2}{10}\\\\a=62.5\ m/s^2[/tex]
So, the acceleration of the object is equal to [tex]62.5\ m/s^2[/tex].
How fast is a ball going when it hits the ground after being dropped from a
height of 16 m? The acceleration of gravity is 9.8 m/s2
A. 22.5 m/s
B. 28.1 m/s
O C. 17.7 m/s
D. 19.3 m/s
Hi there!
[tex]\large\boxed{\text{C. 17.7m/s}}[/tex]
Use the following kinematic equation to solve:
vf² = vi² + 2(ad)
Since the initial velocity is 0 m/s because it started at rest, we can eliminate this part of the equation:
vf² = 2ad
Plug in the given acceleration and distance:
vf² = 2(9.8)(16)
vf ≈ 17.7. The correct answer is C.
What is the wavelength of this wave
[tex]\mathfrak{\huge{\orange{\underline{\underline{AnSwEr:-}}}}}[/tex]
Actually Welcome to the Concept of the Waves.
Wavelength is the distance between two consecutive crest or trough.
hence, here the distance is 10cm
So the wavelength is 10cm
===> 10 cm
Time Dilation. A group of scientists discover a new, rare isotope and are able to store a small amount of it. They determine that the isotope is unstable and half of their sample will decay in 13.0 monthsmonths . The scientists need a new laboratory to properly conduct measurements on the isotope. If laboratory is built before half the sample decays there will still be enough of the isotope available for experiments. However, it will take 21.0 monthsmonths to build the new lab. Fortunately, the scientists can quickly start construction and they have access to a spaceship that can travel at speeds approaching the speed of light c = 3.00
This question is incomplete, the complete question is;
Time Dilation. A group of scientists discover a new, rare isotope and are able to store a small amount of it. They determine that the isotope is unstable and half of their sample will decay in 13.0 months . The scientists need a new laboratory to properly conduct measurements on the isotope. If laboratory is built before half the sample decays there will still be enough of the isotope available for experiments. However, it will take 21.0 months to build the new lab. Fortunately, the scientists can quickly start construction and they have access to a spaceship that can travel at speeds approaching the speed of light c = 3.00 x 10⁸ m/s.
If they place their sample of the isotope on the spaceship, at what speed must it travel in order for the new laboratory to be completed on Earth by the time half of the isotope on the spaceship decays? Assume that it took one month for the scientists to actually start construction and launch the spaceship so half the sample will remain in 12.0 months but it will still take 21.0 months to build the new lab.
Answer:
the required speed is 2.4618 x 10⁸ m/s
Explanation:
Given the data in the question;
Time taken to complete a lab = 21 months
it took them one one to actually start so
Time remaining so that sample only decays by 1/2 = (13 - 1) = 12 months
we need to find at what speed the spaceship should travel so that time on earth ( = 12 months) become time on spaceship ( = 21 months)
we make use of time dilation equation;
t' = t/√( 1 - v²/c² )
where t is time in rest frame = 12 and t' is time in moving frame = 21
so we substitute
21 = 12/√( 1 - v²/c² )
21√( 1 - v²/c² ) = 12
√( 1 - v²/c² ) = 12/21
we square both side
( 1 - v²/c² ) = ( 12/21 )²
( 1 - v²/c² ) = 0.3265
v²/c² = 1 - 0.3265
v²/c² = 0.6735
v² = 0.6735 × c²
v = √0.6735 × √c²
v = 0.8206 × c
given that speed of light c = 3 x 10⁸ m/s
v = 0.8206 × 3 x 10⁸ m/s
v = 2.4618 x 10⁸ m/s
Therefore, the required speed is 2.4618 x 10⁸ m/s
In what order were the following energy sources
discovered by humans
What is the acceleration of a 7 kg object if a force of 63 N is applied?
Answer:
9m/s^2
Explanation:
F=ma
a=F/m
a=63/7
a=9m/s^2
Which subatomic particle identifies the element?
A.
protons
B.
electrons
C.
neutrons
D.
atomic mass
Answer:
A. Protons
Explanation:
Atomic number is an indicator of how many protons an element possesses in its nucleus. We use atomic number to identify an element. For example, carbon has 6 protons and an atomic number of 6.
A screw-jack used to lift a bus is a
A) first order lever
B) second order lever
C) pulley
D) screw
Answer:
c
Explanation:
Which statement about homeostasis is most accurate? *
1:Homeostasis is the ability of the body to change to match the surrounding environment.
Homeostasis is the ability of the body to maintain balance inside the cells, even as the surrounding environment changes
Homeostasis is the ability to fight disease.
Answer:
Homeostasis is the ability of the body to maintain balance inside the cells, even as the surrounding environment changes
The correct option is (1)Homeostasis is the ability of the body to change to match the surrounding environment.
What is Homeostasis?
Homeostasis is the ability of an organism or system to maintain a stable internal environment, despite changes in external conditions. This is achieved through a variety of physiological and behavioral mechanisms that help regulate various bodily functions such as temperature, blood sugar levels, hydration, and oxygen levels.
The process of homeostasis involves the detection of changes in the internal or external environment, followed by a response that helps restore the optimal conditions. For example, if the body's temperature rises above normal levels, the brain triggers sweat production to cool down the body.
Homeostasis is essential for the proper functioning of cells, tissues, organs, and the entire organism. It helps maintain a balance between various bodily functions and ensures that cells have the necessary conditions to carry out their functions. Without homeostasis, cells would be unable to survive and carry out the functions required for life.
Hence the correct statement about homeostasis is, Homeostasis is the ability of the body to change to match the surrounding environment.
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3. If a spring extends by 3 cm when a 4 N weight is suspended from it, find the extension
when the weight is changed to
(a) 8 N
(b) 10 N
(c) 14 N
A child balancing while standing on a chair is demonstrating which type of energy?
A. Potential energy,
B. Nuclear energy,
C. Electrostatic energy,
Answer:
Potential Energy
Explanation:
amount of force times the distance it moves object
work=force×distance this is the formula
PLEASE HELP 15 POINTS AND BRAINIEST!!!
Reporting fake answers
what is tangential velocity
Answer:
Tangential velocity is the linear speed of any object moving along a circular path
Explanation:
Answer:
Tangential velocity is the linear speed of any object moving along a circular path. A point on the outside edge of a turntable moves a greater distance in one complete rotation than a point near to the center.
Explanation:
i hope this helps and can i get brainliest pls?
Using the American Engineering system of units (AES), a) Calculate the weight of a 170.5 lbm person on the surface of the earth, where the local acceleration due to gravity is 32.174 ft/s2 . Report your answer in pound-force, lbf. b) What would be the weight of a 170.5 lbm astronaut on the moon, where the local acceleration due to gravity is 5.32 ft/s2 . Report your answer in pound-force, lbf.
Answer:
a) the weight of the person is 170.5 lbf
b) weight of the astronaut on the moon is 28.2 lbf
Explanation:
Given the data in the question;
a)
we know that;
weight on the surface of the earth = m[tex]g_{earth[/tex]
given that m = 170.5 lbm and g = 32.174 ft/s²
we substitute
weight on the surface of the earth = 170.5 lbm × 32.174 ft/s²
= 5485.667 lbm-ft/s²
1 lbf = 32.174 lbm-ft/s²
so
weight on the surface of the earth = (5485.667 / 32.174) lbf
weight on the surface of the earth = 170.5 lbf
Therefore, the weight of the person is 170.5 lbf
b)
given that;
weight on the surface of the earth = m[tex]g_{moon[/tex]
m = 170.5 lbm and g = 5.32 ft/s²
weight on the surface of the earth = 170.5 lbm × 5.32 ft/s²
= 907.06 lbm-ft/s²
1 lbf = 32.174 lbm.ft/s²
weight on the surface of the earth = ( 907.06 / 32.174 ) lbf
weight on the surface of the earth = 28.2 lbf
Therefore, weight of the astronaut on the moon is 28.2 lbf
You are riding in the passenger seat of a car as it goes around a tight turn. You slide across the seat to the passenger side door. Which statement below properly describes what is happening? a. You are exerting a centripetal force on the door. b. The door and seat are exerting a centripetal force on you that balances the centrifugal force of the turn. c. The car seat exerts a centripetal force on you, but not enough to keep you in place, so the door exerts the rest. d. The centrifugal force is greater than the force of friction between you and the seat, so you slide outward.
Answer:
Explanation:
answer C looks good
there isn't really a "centrifugal " force. :/ when we are pushed "back" in a car seat.. it's not because there is a force pushing us backwards... but a force pushing us forwards.. just like when turning too, a force pushes us into the corner, not a force pushing out of the corner. :)
I'm asking for a quick favor. I'm trying to understand an equation that has to do with Projectile motion, Bernoulli's principle, and Magnus Effect. Basically focused on understanding air resistance on a projectile. I would like to discuss this privately rather than have it on this public forum. I'll give you 100 of my points if you help.
Explanation:
Projectile motion, Bernoulli's principle, and Magnus Effect.
Sure I would be happy to discuss projectile motion!
I'll do it if you mark brainliest :) I need the points thanks
An electron, moving toward the west, enters a uniform magnetic field. Because of this field the electron curves upward. The direction of the magnetic field is An electron, moving toward the west, enters a uniform magnetic field. Because of this field the electron curves upward. The direction of the magnetic field is downward. towards the west. upward. towards the south. towards the north.
Answer:
towards the north.
Explanation:
The uniform magnetic field has strength and direction in all points. The upwards motion of the field or he electronic curves will show a northern direction. Hence, the field can be created by taking the opposite magnetic in the two directions. The straight line of motion of the field will indicate the flow in the north direction. The magnetic field lines will remain parallel and stay uniform to poles.****PLEASE HELP**** WILL MARK BRAINLIEST
Assuming that voltage remains constant, what happens to the current in a
wire if the length of the wire increases?
O A. The current decreases.
OB. The current alternates between high and low values.
O C. The current increases.
O D. The current is not affected by a change in wire length.
Answer:
The Current decreases
Explanation:
HOPE THIS HELPS!
A student at a polymer lab conducted a stress-relaxation experiment on a polymer, whose material response can be modeled by the Maxwell model. In the experiment, a 10-cm-long bar was stretched instantly until the stress reached 200 MPa. After 2 min, the measured stress in the bar was 160 MPa. a) Calculate the relaxation time constant of the polymer. b) If the initial stress was reached by stretching the bar by 16 mm, what is the viscosity of the dashpot in the Maxwell model
Answer: add 10 cm plus 200 mpa divided by 2 min then caculate that into 160 bars.
Explanation:
a) The relaxation time constant of the polymer is approximately 8.9 min.
b) The viscosity of the dashpot in the Maxwell model is approximately 4.55 GPa s.
What is the stress-relaxation model?The stress-relaxation response of the Maxwell model can be modeled by the following equation:
σ(t) = σ₀ exp(-t/τ)
where σ₀ is the initial stress, τ is the relaxation time constant, and t is the time.
a) The relaxation time constant of the polymer:
σ(2 min) = 160 MPa
σ₀ = 200 MPa
160 MPa = 200 MPa exp(-2 min/τ)
Taking the natural logarithm of both sides, we get:
ln(160/200) = -2 min/τ
Solving for τ, we get:
τ = -2 min / ln(160/200) ≈ 8.9 min
Therefore, the relaxation time constant of the polymer is approximately 8.9 min.
b) The displacement of the spring in the Maxwell model can be modeled by the following equation:
x(t) = (σ₀ / G) (1 - exp(-t/τ))
where G is the shear modulus of the polymer. We can use this equation and the given displacement of 16 mm to find the viscosity of the dashpot:
x(t) = 16 mm = 0.016 m
σ₀ = 200 MPa
τ = 6.09 min = 365.4 s
Assume that the shear modulus of the polymer is constant and use the given stress to find it:
G = σ₀ / γ
where γ is the strain induced by the stretching.
Since the bar was stretched by 16 mm and its original length was 10 cm (i.e., 100 mm), the strain is:
γ = 16 mm / 100 mm = 0.16
Therefore,
G = 200 MPa / 0.16 = 1250 MPa
Now we can solve for the viscosity of the dashpot:
η = σ₀τ / x(t)
= (200 MPa) (365.4 s) / (0.016 m)
≈ 4.55 GPa s
Therefore, the viscosity of the dashpot in the Maxwell model is approximately 4.55 GPa s.
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The amplitude of a wave
determines the volume of a
sound.
True
O False
A 20g bullet moving at 200m/s hits a bag of sand and comes to rest in 0.011s, calculate the momentum of the bullet just before hitting the bag
Answer:
momentum = mass * velocity ... kg•m/s
acceleration = v / t = 200 m/s / 11 ms ... m/s^2
force = mass * acceleration = .02 kg * (200 m/s / 11 ms) N
Explanation:
a force is applied to the right to drag a sled to the right across Loosely packed snow with a rightward acceleration (considered friction forces)
Answer:
1.67 m/s²
Explanation:
Total force is;
ΣF = F_f + F_a
From the free body diagram attached, we see that the frictional force F_f is acting in a negative direction.
Thus;
ΣF = -15 + 30
ΣF = 15 N
Now, to get the acceleration, we will use the formula;
ΣF = ma
We are given m = 9 kg
Thus;
15 = 9a
a = 15/9
a = 1.67 m/s²
4. A train starts its journey and accelerates at 5 ms 2. How long does it take for it to reach a velocity of 100 ms??
Answer:
20 seconds
Explanation:
it takes 840s to walk completely around a circular track, moving at a speed of 1.20m/s? what is the radius of the track?
Answer:
160.43 meters
Explanation:
T=(2*pi*r)/v
840=(2*pi*r)/1.2
1008=2*pi*r
504=pi*r
160.43=radius
The distance around the circular track is equal to its circumference. If it takes840 s to complete the path with a velocity of 1.20 m/s then the radius of the path will be 160 m.
What is velocity?Velocity is a physical quantity measuring the distance traveled by unit time. It is a vector quantity thus, characterized by its magnitude and direction. Velocity is usually expressed in m/s.
Velocity is the ratio of distance to the time taken to complete the travel. Thus, greater distance within short time indicates greater velocity.
Given that the time take to complete the circular path = 840 s
velocity = 1.20 m/s
distance = circumference of the circular path = 2πr.
distance = time × velocity
2πr = 840 s × 1.20 m/s
= 1008 m.
Therefore, the radius r of the circular path = 1008 m/ 2 π = 160 m.
Hence, the radius of the circular path 160 m.
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A magnet produces a magnetic field.
Which diagram shows the magnetic field pattern around a bar magnet
You Forgot To Add The Pictures
A 10 kg object moving to the left collides with and sticks to a 3 kg object moving to the right. Which of the following is true of the motion of the combined objects immediately after the collision?
Answer:
"Cannot be determined," if that's an answer choice. It depends on the velocities of both objects, since momentum=mass*velocity.
Explanation: