Question

Suzie (of mass 76 kg) is roller-blading down the sidewalk going 50 miles per hour. She notices a group of workers down the walkway who have unexpectedly blocked her path, and she makes a quick stop in 1.2 seconds. What is Suzie’s average acceleration?

Answer 1

Answer:

Acceleration, $a=-18.62\ m/s^2$

Explanation:

Given that,

Mass of Suzie, m = 76 kg

Initial speed of Suzie, u = 50 mph = 22.35 m/s

Finally, it stops, v = 0

Time, t = 1.2 s

Let a is the Suzie’s average acceleration. It is equal to the rate of change of velocity. Its formula is given by :

$a=\dfrac{v-u}{t}$

$a=\dfrac{0-22.35}{1.2}$

$a=-18.62\ m/s^2$

So, the average acceleration of Suzie’s is $18.62\ m/s^2$ and she is decelerating. Hence, this is the required solution.