Question

A roller coaster's velocity at the top of a hill is 10 m/s. Two seconds later, it reaches the bottom of the hill with a velocity of 26 m/s. What was its acceleration?

Answer 1

The acceleration is `8 m/s^2`.

Explanation:

Acceleration is equal to `"the change in velocity"/"the time to accomplish that"`.

That method of explaining acceleration can be obtained from the basic kinematic formula (using the suvat variables)

`v = u + a*t`.

Rearranging the variables as follows

`a*t = v - u`

`a = (v - u)/t`
That is equivalent to the explanation I gave you in words.

Therefore,
`a = (26 m/s - 10 m/s)/(2 s) = 8 m/s^2`

I hope this helps,
Steve