Question

A train is happily moving at a speed of 30mi/hr when the engine gives out all for sudden. If it

takes 20 minutes for the train to come to rest, what is the average acceleration? (Give your answer
in m/s².)

Answer 1

-0.011176 m/s²

Step-by-step explanation:

You want the acceleration in m/s² of a train that comes to rest from 30 mi/h after 20 minutes.

Acceleration

The acceleration is the change in velocity divided by the change in time.

`-\frac{\frac{30\text{ mi}}{\text{h}}}{20\text{ min}}=\frac{30\text{ mi}}{20\text{ h$\cdot$min}}*\frac{1609.344\text{ m}}{1\text{ mi}}*\frac{1\text{ h}}{60\text{ min}}*\left(\frac{1\text{ min}}{60\text{ s}}\right)^2\\\\=-\frac{30\cdot1609.344\text{ m}}{20\cdot60^3\text{ s}^2}=\boxed{-0.011176\text{ m/s}^2}`