Calc motion problem help

[jschwa1]

A car accelerates from rest with an acceleration of a = 0.3t mph/(hr sec), where t is time in sec. If velocity is the integral with time of acceleration, and distance is the integral with time of velocity, how far has the car traveled when t = 80 sec?

I think that the units are what is giving me a tough time on this problem. The answer is to be given in feet, and the solution is 10.4 ft, but I can't figure out how to get it. :?

 

[Deleted member 4993]

A car accelerates from rest with an acceleration of a = 0.3t mph/(hr sec), where t is time in sec. If velocity is the integral with time of acceleration, and distance is the integral with time of velocity, how far has the car traveled when t = 80 sec?

I think that the units are what is giving me a tough time on this problem. The answer is to be given in feet, and the solution is 10.4 ft, but I can't figure out how to get it. :?

Convert everything to seconds and ft.

Tell us what do you get.

 

[soroban]

Hello, jschwa1!

Can you give us the original wording of the problem?

A car accelerates from rest with an acceleration of a = 0.3t mph/(hr sec) where t is time in sec. .What does this mean?

If velocity is the integral of acceleration, and distance is the integral of velocity, how far has the car traveled when t = 80 sec?

The solution is 10.4 ft.

 

[galactus]

The car traveled 10.4 feet in 80 seconds?. That's mighty slow. That's about .08 mph.

Are you sure the problem is worded correctly?.

 

[jschwa1]

This is the exact wording of the problem. I figured it out. To convert the units, you have to multiply by 5280 and divide by 3600 ^ 2. I was forgetting to square the 3600. Thanks