Multiple choice with justification - 1. A race car completes exactly 10 laps around an oval track. Which of of quantities concerning its motion would both have values of zero? a. displacement, average velocity b. average speed, average acceleration c. distance, average speed d. average speed, average velocity e. displacement, average speed Justify your answer: displacement, average velocity will both have values of zero because Since it is an oval track the Person keeps running to the same spot 10 times where they originally started 2. An object is thrown vertically upward with a speed of 25 m/s. How much time passes before it comes back down at 15 m/s? (Air resistance is negligible.) a. 1.0 s b. 4.1 s C. 9.8 s d. 18 s e. 27 s Justify your answer: 1 = 0-25 mls = 2.555 t +t' = 2.55 5 + 1.53 = 9. 81 m / 52 3. For a javelin thrower to maximize her throwing distance, she should release the javelin at an angle a. of 450 b. of less than 450 c. of greater than 450 d. dependent on the javelin's speed upon release e. dependent on the thrower's strength