Question

During a race, a runner runs at a speed of 6 m/s. Four seconds later, she is running at a speed of 10 m/s. What is the runner's acceleration?

Answer 1

1 m/s². A runner that change is speed from 6 m/s to 10 m/s has an aceleration of 1 m/s².

the key to solving this problem is using the kinematics equation $a=\frac{v_{f} -v_{0}}t}$ which means that the aceleration is related to a change of velocity in an interval of time.

We know that the runners runs at a initial velocity of 6 m/s, four seconds later, she is running at a speed of 10 m/s.

$a=\frac{10\frac{m}{s}-6\frac{m}{s}}{4s}  \\a=1\frac{m}{s^{2} }$