Question

How long does it a take a runner, starting from rest to reach max speed, 30 f/s given acceleration 8 f/s^2? After finding the time, calculate the distance traveled in that time.

Answer 1

Explanation:

Given that,

Initial sped of the runner, u = 0

Final speed of the runner, v = 30 ft/s

Acceleration of the runner, $a=8\ ft/s^2$

Let t is the time taken by the runner. It can be calculated using first equation of motion as :

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

$t=\dfrac{30-0}{8}$

t = 3.75 seconds

Let s is the distance covered by the runner. Using the second equation of motion as :

$s=ut+\dfrac{1}{2}at^2$

$s=\dfrac{1}{2}\times 8\times (3.75)^2$

s = 56.25 feet

Hence, this is the required solution.