Question

A truck traveling at 61 mph brakes to a stop in 231 feet. what was the average acceleration and stopping time?

Answer 1

The average acceleration is -5.21 m/s² and the stopping time is 5.2 sec.

Given,

Final velocity, v = 0

Initial velocity, u = 61 mph

mph to km/h

u = 97.6 km/h

Or, u = 27.11 m/s

Displacement, s = 231 feet

Or, s = 70.4 meter

By using the third equation of motion, we get

v² - u² = 2as

0 - (27.1)² = 2 × a × 70.4

Or, acceleration(a) = -5.21 m/s²

Now, by the first equation of motion,

v = u + at

Or, - u = at

-27.11 = -5.21 × t

Or, t = 27.11/5.21

t = 5.2 sec

The stopping time (t) is 5.2 sec

Hence, the average acceleration is -5.21 m/s², and the time is 5.2 sec.

To learn more about acceleration and time, visit: brainly.com/question/25007278

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