AP Physics Midterm Review

1. A particle move along the x-axis according to the equation, x = 2.00 + 3.00 t –t4, where x is in meters and t is in seconds. At t = 3.00 s, find:

a. The position of the particle.

b. Its velocity.

c. Its acceleration.

2. A 3.00 kg mass has an initial velocity of ˆ ˆ(6.00 2.00 )ov i j � m/s and some time

later has a velocity of ˆ ˆ(8.00 4.00 )fv i j � m/s. a. What is the initial kinetic energy?

b. How much work is done on the object during the time interval?

3. A particle moving in the xy plane undergoes a displacement ˆ ˆ(2.0 3.0 )d i j m � as a constant force, ˆ ˆ(5.0 2.0 )F i j N � acts on the particle.

a. Calculate the magnitude of the displacement and the magnitude of the force.

b. Calculate the work done by the force.

4. A motorist is travelling at 18.0 m/s when he sees a deer in the road 42.0 m ahead. a. If the maximum negative acceleration of the vehicle is -4.75 m/s2, what is

the maximum reaction time, t of the motorist that will allow him to avoid hitting the deer?

b. If his reaction time is actually 0.5500 s, how fast will he be travelling when he hits the deer?

5. A basketball player who is 2.00 m tall is standing on the floor 10.0 m from the basket. If he shoots the ball at a 40.0o angle with the horizontal, at what initial speed must he throw so that it goes through the hoop without striking the backboard? The basket height is 3.05 m.

6. While moving in, a new homeowner is pushing a box across the floor at a constant velocity. The coefficient of static friction between the box and the floor is 0.41. The pushing force, FP is directed downward at an angle, θ below the horizontal.

a. What is the value of FP if θ = 30.0o and m = 24.0 kg?

b. When the angle, θ is larger than a certain value, it is impossible to move the box, no matter how large the pushing force. Find that value of θ.

7. A bobsled rounds a curve by ‘banking’ up on the wall, so that the normal force provides a centripetal force.

a. If a bobsled of rounds a curve at 10.0 m/s (the radius of curvature is 5.00 m), what angle should the wall make with the horizontal so that the sled safely rounds the curve?

b. If there was friction between the sled and the track with m = .010, how slow could the sled go and still make the turn?

c. If the track was perfectly flat, with a coefficient of static friction of m = 0.10 between the ice and the sled, how fast could the sled go around the turn?

8. A crate of mass 10.0 kg is pulled up a rough incline with an initial speed of 1.50 m/s. The pulling force is 100 N parallel to the incline, which makes an angle of 20o with the horizontal. The coefficient of kinetic friction is 0.400 and the crate is pulled 5.00 m.

a. How much work is done by gravity?

b. How much energy is lost because of friction?

c. How much work is done by the 100 N force?

d. What is the change in kinetic energy of the crate?

e. What is the speed of the crate after it has been pulled 5.00m?