Question

4. A rifle is aimed horizontally at a target 50 m away. The bullet hits 1.25 m below the target. (a) What was the bullet’s flight time? (b) What was the bullet’s speed as it left the barrel?

5. A 1000-kg car traveling at a speed of 40 m/s skids to a halt on wet concrete where µk = 0.8. How long are the skid marks?

9. A curve at a racetrack has a radius of 100 m and is banked at an angle of 45 degrees. On a rainy day, the coefficient of static friction between the cars’ tires and the track is 0.6. What is the maximum speed at which a car could go around this curve without slipping?

10. Ships A and B leave port together. For the next two hours, ship A travels at 30 mph in a direction 30 degrees west of north while ship B travels 60 degrees east of north at 20 mph. (a) What is the distance between the two ships two hours after they depart? (b) What is the speed of ship A as seen by ship B?

Answer 1