1. What is the force of sliding friction between a block and the ground if the coefficient of kinetic friction is μk = 0.28 and the block weighs 17 N?
a. 81 N b. 17 N c. 4.8 N d. 61 N e. 1.3 N
2. A 300 kg spacecraft weighs 760 N on the surface of Planet Zphyz. What is the acceleration due to gravity on the planet’s surface?
a. 6.0 m/s^2 b. 2.5 m/s^2 c. 5.1 m/s^2 d. 0.0 m/s^2 e. 0.39 m/s^2
3. A 4900 kg jet reaches a takeoff velocity of 90 m/s after accelerating from rest for 800 m down the runway. What net force is required from the jet's engines?
a. 970 N b. 44000 N c. 3.5 x10^8 N d. 25000 N e. 50000 N
4. The coefficient of kinetic friction between a floor and a box made of wood is μk = 0.13. How far does the box slide if it has an initial speed of vo = 5.0 m/s?
a. 29 m b. 9.8 m c. 39 m d. 17 m e. 11 m
5. What is the acceleration due to gravity on Planet X if someone who weighs 900 N on Earth weighs 2400 N on Planet X?
a. 26 m/s^2 b. 3.7 m/s^2 c. 9.8 m/s^2 d. 92 m/s^2 e. 240 m/s^2
6. A 2.4 kg box is moving at 21 m/s on a frictionless plane. When will it stop?
a. 23 b. never s c. 0.11 s d. 8.8 s e. immediately
