Basic kinematics variables: Suppose that a car traveling to the west (the -x direction) begins to slow down as it approaches a traffic light. Which statement concerning its acceleration in the x direction is correct?
A) Both its acceleration and its velocity are positive.
B) Both its acceleration and its velocity are negative.
C) Its acceleration is positive but its velocity is negative.
D) Its acceleration is negative but its velocity is positive.

Question

Quizplus · Accepted Answer

Since the car is slowing down while moving to the west (the -x direction), its velocity is negative. To slow down, the acceleration must be in the opposite direction of the velocity, which means the acceleration is positive.

Basic Kinematics Variables: Suppose That a Car Traveling to the West