SPH3U
Dynamics Problem Set - Dynamics + Kinematics
1. A tennis racket, in contact with a 55-g ball for 0.0050 s, changes the ball’s velocity from 32 m/s in one direction to 42 m/s in the opposite direction. What average force does the racket exert on the ball?
2. A 52 kg diver steps off of a 9.0 m diving board at the same time as a 1.0 x 102 kg diver. Compare the times taken for the two divers to reach the water.
3. A drag racing car starting from a standstill can reach a speed of 320 km/h in 6.5 s by exerting an average horizontal force of 1.52 x 104 N on the pavement. If friction equals 5.2 x 103 N, what is the mass of the car?
4. What force must be exerted to make a 5.0 kg object travel 6.0 m forward in 4.0 s? Assume the object starts at rest and that the coefficient of kinetic friction between the object and the surface it sits on is 0.40. Ignore the initial static friction.
5. Find the magnitude of the force needed to slide a 4.0 kg block along a tabletop at a constant velocity. ? (= 0.05)
6. Find the magnitude of the acceleration of a 2980 kg car skidding to a stop if =0.40.
7. A net force of 350 N [left] applied to an object changes the object’s velocity from 12 m/s [left] to 24 m/s [left] in 4.0 s. What is the mass of the object?
8. A 5.0 x 10 kg stationary box is pushed with a force of 525 N [E]. If the coefficient of kinetic friction between the box and the ground is 0.78, what will be the box’s velocity after 1.8 s (ignore the initial static friction)?
9. A 1.0 x 103 kg car is traveling at 8.0 x 10 km/h when the brakes are locked and the car begins skidding on pavement. If the coefficient of kinetic friction between the car and the road is 0.90, how long, in seconds, will it take the car to stop?
10. Determine the coefficient of friction between a 3kg textbook and the desk if the book was initially sliding along the desk and takes 0.6 second and 75 cm to come to a complete stop. (Give your final answer to one significant figure for this problem).
Dynamics Problem Set - Dynamics + Kinematics
1 / 2 / 3 / 4 / 5814 N [opposite the ball’s original velocity] / The times are the same (1.36s) / 731 kg / 23.4 N [forward] / 1.96 N
6 / 7 / 8 / 9 / 10
3.92 m/s2 / 117 kg / 5.14 m/s [E] / 2.52 s / µk = 0.4