Question

A boat moving 18ft/sec slows to a stop in 9 seconds. What is it’s acceleration?

Answer 1

Given:

The initial velocity of the boat is,

`u=18\text{ ft/s}`

The final velocity of the boat is,

`v=0`

The boat stops after,

`t=9\text{ s}`

If the acceleration is a, we can write,

`v=u+at`

Substituting the values we get,

`\begin{gathered} 0=18+a*9 \\ a=-(18)/(9) \\ a=-2ft/s^2 \end{gathered}`

Hence the acceleration is -2 ft/s^2.