Other Physics Answers

Use the information below to answer the following 2 questions.

A rubber-band slingshot is drawn back is drawn back 0.15 m with a force of 28 N and shoots a 28-g stone. Solve using energy considerations. Recall from the previous lesson that E_p = ½ kx². Since F = kx, E_p = ½ Fx.

1.The initial speed of the stone if the rubber band is released is___m/s (Give your answer with the correct number of sig digs and do not include units).

2.The maximum height of the stone if it is shot straight up is ___m. (Give your answer with the correct number of sig digs and do not include units).

3.The kinetic energy of a 20.0-N object is 5.00 × 10² J. The speed of this object is ___m/s. (Give your answer with the correct number of sig digs and do not include units).

4.A 10.0-N object is accelerated uniformly from rest at a rate of 2.5 m/s². The kinetic energy of this object after it has accelerated a distance of 15.0 m is ___J. (Give your answer with the correct number of sig digs and do not include units).

1.A 90.0-N box is pulled 10.0 m along a level surface by a rope. If the rope makes an angle of 20.0° with the surface, and the force exerted through the rope is 75.0 N, the work is done on the box is ___J. (Give your answer with the correct number of sig digs and do not include units)

2.A 25.0-N object is held 2.10 m above the ground. The potential energy of the object with respect to the ground is ___J. (Give your answer with the correct number of significant digits and do not include units).

Use the information below to answer the following 4 questions.

A 10.0-kg object is accelerated horizontally from rest to a velocity of 11.0 m/s in 5.00 s by a horizontal force.

1.The acceleration of the object is ___m/s². (Give your answer with 3 sig digs and do not include units).

2.The horizontal force given to the object is ___N. (Give your answer with 3 sig digs and do not include units).

3.The distance travelled by the object is ___m. (Give your answer with 3 sig digs and do not include units).

4.The work done on the object is ___J. (Give your answer with 3 sig digs and do not include units).

1.A 60.0-kg student runs at a constant velocity up a flight of stairs. If the vertical distance of the stairs is 3.2 m, the work done against gravity is ___x10³ J (Give your answer with the correct number of sig digs and do not include units).

Question 1 options:

A satellite is located 450 km above the surface of the Earth. It would take the satellite ___x10³ s to complete one orbit of the Earth. (Give your answer with 3 sig digs and do not include units)

Question 2 options:

An asteroid has a mean radius of orbit of 4.6 x 10¹¹ m. Its orbital period around the sun is ___x10⁸s. (Give your answer with 2 sig digs and do not include units)

Question 3 options:

For a satellite to have a speed of 7400 m/s, it must be ___x10⁵ m above the earth surface. (Give your answer with 3 sig digs and do not include units)

question 4

If a small planet were located 7 times as far as the Earth's distance from the Sun, it period is ___ earth years? (Give your answer with 3 sig digs and do not include units)

Jen is stockpiling his treats in a hole. He sets a 500g box of treats on a ramp angled at 65 degrees. The core didn’t of friction is 0.15. 

1. how fast will the box accelerate down the ramp 
2. If the ramp is 1.5m, how long will it take the box to get to the bottom 

A block with mass m is dragged across a horizontal surface at constant speed v by a force of magnitude Fapp, which acts at an angle of θ above the horizontal surface. The coefficient of kinetic friction between the block and the surface is coefficient of kinetic friction µ_k. The normal force exerted on the block by the horizontal surface is:

Question 2 options:

a) 

No option is correct.

b) 

µk (mg- Fapp sinθ).

c) 

µk (mg + Fapp cosθ).

d) 

µk mg.

e) 

µk (mg - Fapp cosθ).

f) 

µk (mg + Fapp sinθ).

A car starts from rest and accelerates uniformly at a rate of 2 m.s-2 for 20 s. It then maintains a constant velocity for 10 s. The brakes are then applied, and the car is uniformly decelerating and comes to rest in 5 s. What is the maximum velocity and the deceleration in the last 5 seconds?

Question 1 options:

a) 

20 m/s and 4 m/s².

b) 

10 m/s and 2 m/s².

c) 

No option is correct.

d) 

30 m/s and 6m/s².

e) 

40 m/s and 8 m/s².