1. 9) A 0.60-kg rock is swung in a circular path and in a vertical plane on a 0.50-m-length string. At the top of the path, its speed is 4 m/s. What is the tension in the string at that point? answer - 13.2N
2. 9) A skier starts from rest from the top of a 40 m high slope which makes 40 degrees with the ground. Coefficient of friction is 0.1 What is the velocity of the skier at the bottom of the ramp? answer - 24.4m/s
3. 6) A 2.0-kg mass moving at 5.0 m/s suddenly collides head-on with a 3.0-kg mass at rest. If the collision is perfectly elastic, what is the speed of the masses just after the collision? Is the kinetic energy conserved? answer V1f = -1m/s and V2f = 4m/s. Energy conserveed
4. 7) A 0.35-kg toy car moving with 0.65 m/s hits a 0.20 kg toy truck moving in the opposite direction with the speed of 0.40 m/s. After the collision, the toy car bounces back with a speed of 0.35 m/s. What is the speed of the toy truck after the collision? answer V2 = 0.3m/s