Section I Short Answer. 1 mark each. 1. Sketch a velocity time graph for a ball thrown up into the air 2. A ball is dropped from a tall cliff. How far does it fall in 3.5 seconds? 3. A car moving at 50 kph jams on the brakes and stops in 35 metres. Find its acceleration. 4. A 300 m long train moving at 8 m/s encounters a 400 m long train moving at 10 m/s in the opposite direction. How long does it take the trains to completely pass each other? 5. A person heads straight across a 30m wide river at a swim speed of 3 m/s. The river current is 5 m/s. What is their speed and direction relative to shore? current = 5m/s swim=3m/s 6. A projectile is thrown horizontally at 5 m/s from the top of a 25 m high cliff. Find the range of this projectile. 5 m/s 7. A projectile is launched at 40 m/'s and at an angle of 250 on level ground. Find the speed of this projectile after 3 seconds.8. A projectile is launched at an angle from the top of a 40 m high cliff. The projectile's initial velocity is 20 m's at an angle of 159. Find the flight time of this projectile 40m 9. A 50 kg person in in an elevator accelerating up at 0.75 m/s-. What is the normal force that acts on the person? 10. A 20 kg object is dropped. While falling, it experiences an average air resistance force of 40N. How long will it take the mass to fall 30 metres. 1 1. Find the acceleration of this system 7 N force 2 kg 1.5 kg frictionless surface 12. Find the acceleration of this system. 4.3 kg 8 kg 13. In #12, write a force equation for the 8 kg mass 14. The 8 kg mass slides down the ramp. Write a force equation.8 kq. H-0.15 25 15. Find the acceleration of the mass in #14 16. Write a force equation for the 6 kg mass 6 kg frictionless surface 3 kg 28 17. Find the acceleration of this system. 18. Write force equations for this system. (x and y) 160 N 15 50 kg M=0.1 19. Find the normal force acting in #18 20. Find the acceleration in #18.Section II. Long Answer. Recopy diagrams into exam book. Show all work. FBD must be shown. 1. For the projectile below, find a) the maximum height b) the flight time c) the range d) the velocity (incl direction) after 2.5 seconds 30 m/s O 20' 40m 5.37 m; 4.10 sec; 1 15 m; 31.6m/s, 27"SE) 2. The system below is acted upon by a horizontal force F of 150 N. If the friction co-efficient is u=0.03, find the acceleration of the system. Think carefully about and explain thoroughly the direction of friction. (0.39 m/s-) F 40 ka 30 10 kg 30