Question

a car travels on a straight road.

a) starting from rest, the car is going 44 ft/s (30 mi/h) at the end of 5.0 s. What is the car's average acceleration in ft/s^2

b) in 4.0 more seconds, the car is going 88 ft/s (60 mi/h). what is the car's average acceleration for this time period?

c) the car then slows to 66 ft/s (45 mi/h) in 3.0 s. what is the average acceleration for this time period?

d) what is the overall average acceleration for the total time?

Answer 1

a = change in velocity/change in time
= 44/5 = 8.8 ft/s^2

a = same formula = (88-44)/4 = 11 ft/s^2

a = (66 -88)/3 = -7.33 ft/s^2

sum of a*t / total t
(8.8*5 + 11*4 - 7.33*3)/12
= 5.5 m/s^2

Answer 2

How to solve