Question

a runner accelerated to 4 m/s^2 for 20 seconds before winning the race.How far did he/she run?

Answer 1

Answer:

s=800 m

Explanation:

Given that,

Acceleration of a runner, a = 4 m/s²

Time, t = 20 seconds

We need to find the distance covered by her. Initially, she was at rest. It means its initial velocity is equal to 0. So, using second equation of motion as follows :

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

Herre, u = 0

$s=\dfrac{1}{2}at^2\\\\s=\dfrac{1}{2}\times 4\times (20)^2\\\\s=800\ m$

So, she will cover a distance of 800 m.