Question

a runner starts a race from rest and begins to run in a straight line. she runs for the first 10 seconds at a rate of acceleration of 4 m/s^2.
a) what is the runners initial velocity?
b) what is the runners final velocity?
c) how far has the runner gone in 10 seconds?

Explanation:

Step1: Identify initial velocity

The runner starts from rest, so $u = 0\ m/s$.

Step2: Calculate final velocity

Use the equation $v=u + at$. Given $u = 0\ m/s$, $a = 4\ m/s^{2}$, and $t = 10\ s$. Then $v=0+4\times10=40\ m/s$.

Step3: Calculate distance traveled

Use the equation $s=ut+\frac{1}{2}at^{2}$. Substitute $u = 0\ m/s$, $a = 4\ m/s^{2}$, and $t = 10\ s$. So $s=0\times t+\frac{1}{2}\times4\times10^{2}=200\ m$.

Answer:

a) $0\ m/s$
b) $40\ m/s$
c) $200\ m$