Question

Two identical objects. A and B, move along straight, parallel, horizontal tracks. The graph on the right represents the velocity as a function of time for the two objects.

(a) Indicate which of the two objects, if either, has a decreasing speed during the time interval shown. If neither object has a decreasing speed, indicate this specifically. Briefly explain your answer.
(b) Indicate at approximately which time or times, if any, the objects are moving at the same speed. If objects A and B are never moving at the same speed during the interval shown, indicate this specifically. Briefly explain your answer.
I would appreciate help with this, thank you!

Answer 1

(a) Object A has a decreasing speed during the time interval shown. This is because its velocity is decreasing (becoming less positive) over time, indicating a decrease in speed. Object B, on the other hand, has a constant speed during the time interval shown because its velocity is constant (zero) over time.

(b) Objects A and B are moving at the same speed at approximately t = 4 seconds and t = 8 seconds. This is because the velocity vs. time graph for object A intersects the velocity vs. time graph for object B at these times, indicating that their velocities are equal at these times. At all other times during the interval shown, the two objects are not moving at the same speed.