Which of these is an example of deceleration?
A. a roller coaster moving down a steep hill
B. an airplane following a straight flight path
C. a bird taking off for flight
D. a car approaching a red light
A. a roller coaster moving down a steep hill
B. an airplane following a straight flight path
C. a bird taking off for flight
D. a car approaching a red light
1 Answer
Feb 15, 2017
D
Explanation:
For A, the rollercoaster will either be accelerating or have reached its terminal velocity.
B is ambiguous. A plane could cut its engines and glide, so thereby decelerate (due to drag) while moving in a straight line. However, the implication is that is hasn't so we should probably discount this
C A bird taking off would be increasing its velocity so will be accelerating
D - a car reduces it velocity to nil when approaching a red light so it will be decelerating