CSEC Physics Practice Test : Motion in a straight line Name:_________________________________________ Marks: _______/40 Date:_____________ Section A 1. Unless acted on by an external net force, an object will stay at rest or A. come to rest. B. decelerate at a constant rate. C. slow down from a given speed. D. continue to move in a straight line at a constant speed. 2. An object is sliding down a smooth incline. If friction is negligible, the object has A. constant velocity. B. constant momentum. C. constant acceleration. D. constant displacement. 3. What is the frictional force due to air resistance on a 0.50 kg object falling vertically with an acceleration of 8.5 m/s2 ? A. 0.65 N B. 4.3 N C. 4.9 N D. 9.2 N 4. The frictionless system shown below accelerates at 1.60 m/s2 when released. Find the tension in the string while the system is accelerating. A. 3.20 N B. 16.4 N C. 19.6 N D. 22.8 N 5. A 75 kg man stands on a scale while accelerating upwards in an elevator. If the scale reads 850 N, what is the magnitude of the acceleration of the elevator? A. 1.2 m/s2 B. 1.5 m/s2 C. 9.8 m/s2 D. 11 m/s2 6. Which of the following is NOT a statement of one of Newton's laws of motion? A. For every action force, there is an equal and opposite reaction force. B. If no net force acts on an object, the object will remain at rest, or continue to move at a constant velocity. C. The acceleration of freely falling objects is proportional to their mass. D. If a net force does act on an object, the object will accelerate in the direction of the net force. 7. Which of the following graphs shows the relationship between acceleration and net force? 8. Graph illustrating velocity of object with time is called A. velocity-speed graph B. velocity-time graph C. speed-time graph D. velocity-displacement graph D. time taken per unit displacement 10. The speed of a truck is 40 ms-1, after 10 seconds its speed decreases to 20 ms-1, its acceleration is A. B. C. D. 9. Velocity is the A. distance covered per unit time B. displacement covered per unit time C. time taken per unit distance −1 m s-2 −4 m s-2 −2 m s-2 −5 m s-2 Section B 1. Explain the difference between speed and velocity. (2 marks) 2. Define acceleration. (1 mark) 3. Sketch a distance – time graph for a. An object at rest at the origin (starting point). b. An object at rest 5 m from the origin c. An object moving at a steady speed (3 marks) 4. State the relationship between the area under a velocity-time graph and distance moved (1 marks) 5. 6. 7. Answer the following questions about the car whose motion is graphed below: a. When was the car 20 m west of the origin (assuming west of origin is -ve and east of origin is +ve)? b. where was the car at 50 s? c. The car suddenly reversed direction. When and where did that occur? (3 marks) 8. A 4500 kg helicopter accelerates upward at 2.0 m/s2. What lift force is exerted by the air on the propellers? (2 marks) 9. 10. 11. 12. Nyanza and Joshua are racing their remote-controlled model cars down a flat road. Information on their motion is shown in the table. Nyanza: distance (m) 4 8 12 16 20 Nyanza: time (s) 1 2 3 4 5 Joshua: distance (m) 3 6 9 12 15 (a) Plot a graph of distance against time for both cars. Joshua: time (s) 1 2 3 4 5 [3] (i) Calculate the average speed of both for the 5 seconds. (ii) Whose car travelled faster? [3 marks] ................................................................................................................................................. [1marks] (c) Joshua’s car veers off course and collides with a wall. Describe the energy changes which take place during the collision. ................................................................................................................................................... [1mark] 13. Usain Bolt won the 200m at the 2008 Olympic Games in a new World record time of 19.30s. (a) Write down the equation you could use to work out his average speed in the race. .................................................................................................................................................. [1 mark] (b) Calculate his average speed. ................................................................................................................................................................ ................................................................................................................................................................ ................................................................................................................................................ [2 marks] (c) He reached a velocity of 7.9 m/s, two (2) seconds after the start of the race. How far had he run in the first 2s? (You may assume he accelerates at a constant rate.) ................................................................................................................................................................ ................................................................................................................................................................ ................................................................................................................................................ [2 marks] End of Unit Test