Question

A runner covers the last straight stretch of a race in 8s.During that time he speeds up from 7 m/s to 9m/s. What is the acceleration

Answer 1

Given

Time taken is t=8 s.

The initial speed is u=7 m/s

The final speed is v=9 m/s.

To find

The acceleration

Step-by-step explanation

We know the acceleration is the ratio of the difference in the speed to the time taken.

Thus,

`\begin{gathered} a=(v-u)/(t) \\ \Rightarrow a=(9-7)/(8) \\ \Rightarrow a=(2)/(8)=(1)/(4)=0.25\text{ m/s}^2 \end{gathered}`

Conclusion

The acceleration is

`0.25\text{ m/s}^2`