Question

you are walking at 9 m/s. 300 seconds later, your speed is 6 m/s. acceleration occurred because you changed directions. acceleration occurred because speed decreased. acceleration occurred because speed increased.

Explanation:

Acceleration is a change in velocity (speed or direction). Here, speed decreased from 9 m/s to 6 m/s. The first option's direction change isn't indicated, and the third is wrong (speed decreased). So the correct reason is speed decrease.

Answer:

B. Acceleration occurred because speed decreased.