1. 5-I TEM MCQ S IN K INEMATICS

2. 1) What do you call the total length traveled by an object in a given time? a. Distance b. Displacement c. Speed d. Acceleration

3. 2) The slowing down of an object’s motion is more appropriately called _______. a. Deceleration b. Displacement c. Speed d. Velocity

4. 3) A bus moves along PIE at a constant speed of 60 kph in 2 hours. What is its acceleration? a. 0 ms -2 b. 10 ms -2 c. 60 ms -2 d. 120 ms -2

5. 4) A car moves at a uniform speed of 20 ms -1 in 1.5 minutes. How far did it go during that period? a. 0.6 km b. 1.8 km c. 3.0 km d. 4.1 km

6. 5) A train comes to a stop in 45 seconds from a speed of 400 m/s. Calculate its deceleration. a. About 9 ms -2 b. About 12 ms -2 c. About 15 ms -2 d. About 19.6 ms -2

7. Correct! Congratulations. View explanation #1.

8. Correct! Congratulations. View explanation # 2.

9. Correct! Congratulations. View explanation # 3.

10. Correct! Congratulations. View explanation # 4.

11. Correct! Congratulations. View explanation # 5.

12. Wrong! You may try again.

13. Explanation # 1: Total length is the total distance d traveled by an object. Given time is the time elapsed t to travel a certain distance. If you divide distance by time, you get speed v. In symbols, v = d/t

14. Explanation # 2: In the physical world, the slowing down or coming to a stop of an object is called negative acceleration or, more appropriately, deceleration. It happens when the final velocity of an object is less than its initial velocity.

15. Explanation # 3: An object that moves with a constant speed has zero acceleration. You can prove this mathematically by using the equation: You can clearly infer from the equation that if v i and v f are the same, the acceleration becomes zero, no matter how long the object travels. a = (v f -v i )/t

16. Explanation # 4: Time must be expressed in seconds. By converting, 1.5 minutes is equal 90 seconds. Since v = d/t, and substituting the values: v = d/t 20 ms -1 = d / (90s) d = (20 ms -1 ) (90s) d = 1800 m = 1.8 km

17. Explanation # 5: In the physical world, deceleration means slowing down of an object’s motion. In the problem, v i = 400m/s, v f = 0, and t = 45 s. Since a = (v f -v i )/t, and substituting the values: a = (v f -v i )/t a = (0 m/s – 400 m/s) / 45 s a = 8.88 m/s 2

18. T HANK YOU ! This is the end of this test.

19. Prepared by: RONALD P. DIANA Ramon Magsaysay (Cubao) HS – Philippines Under the supervision of: Prof. PHILIP WONG Nat’l. Inst. Of Education (NIE) – Singapore