Question

A car starts from rest and accelerates along a straight line path in one minute. It finally attains a velocity of 40 meters/second. What is the car's average acceleration?
A.) 1.5 meters/second2
B.) 1.5 meters/second
C.) 0.66 meters/second2
D.) 0.66 meters/second

Answer 1

To answer this question, we will use the equation of motion which states that:
V = u + at where:
V is the final velocity = 40 meters/second
u is the initially velocity. Since the car starts from rest, this means that u = 0
a is the acceleration we need to calculate
t is the time = 1 minute = 60 seconds

Substitute with the givens in the above mentioned equation to get the acceleration as follows:
V = u+at
40 = 0 + 60a
a = 40/60 = 2/3 = 0.667 meter / sec^2

Based on the above calculations, the right choice is:
c. 0.66 meters / second^2

Note that choice D has the right value but the wrong units. Therefore, D is not the correct choice.