Calculate Acceleration for Race Car Driving

[Thousands]

1. If your car goes from 0 mi/h to 40 mi/h in
5 s, what is your average acceleration?
Answer in units of
miles
h · s



2. i think i multiply 40 times the 5 and then the answer by something else. I'm not too sure

 

[berkeman]

1. If your car goes from 0 mi/h to 40 mi/h in
5 s, what is your average acceleration?
Answer in units of
miles
h · s



2. i think i multiply 40 times the 5 and then the answer by something else. I'm not too sure

The acceleration will be the change in velocity, divided by the time it took to change that velocity. Think of it this way -- the smaller the time, the higher the acceleration, right?

Now what do you think you do to get the answer?

 

[Thousands]

then i just divide 40 by 5 right?

 

[berkeman]

then i just divide 40 by 5 right?

Yes. The mixed units for the answer that they ask for are quite strange, and you normally would not leave your answer in mixed units, but they seem to be doing that just to make it easier for you to do the first steps of the math.