Question

A sprinter begins from rest and accelerates at the rate of 2 m/s^2 for .12 mi, what is the sprinters velocity?

Answer 1

Given:

Initial velocity = 0 m/s

Acceleration = 2$\frac{m}{s^{2} }$

Time = 12 minutes = 12 × 60 = 720 second

To find:

Final velocity = ?

Formula used:

v = u + at

v = final velocity

u = initial velocity

a = acceleration

t = time

Solution:

According to first equation of motion,

v = u + at

v = final velocity

u = initial velocity

a = acceleration

t = time

v = 0 + 2(720)

v = 1440 $\frac{m}{s}$

The sprinters velocity is 1440 $\frac{m}{s}$

Answer 2

Answer:

v = 14.4 m/s

Explanation:

It is given that,

Initial speed of the sprinter, u = 0

Acceleration of the sprinter, $a=2\ m/s^2$

Time taken, t = 0.12 min = 7.2 s

Let v is the final speed of the sprinter. It can be calculated as :

v = u + at

$v=0+2\ m/s^2\times 7.2\ s$

v = 14.4 m/s

So, the sprinter's velocity is 14.4 m/s. Hence, this is the required solution.