(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

The graph shows the speed as a function of time for a minivan, coasting on neutral along a straight, level road, loaded with windsurfing equipment and towing a boat. The total mass is 2500 kg, weight= 5512lbs. Find the size of the force due to wind and rolling friction when the van speed is 44.17 mph. (1 mph=0.447m/s)

2. Relevant equations

F=ma

3. The attempt at a solution

I don't think anyone needs to see the graph to understand my problem. Well I hope.

I understand that a= delta v/delta t. But whenever I use the equation I get an acceleration that does not work. Then I thought that since the equation wants the force at 44.17 mph, that I need to find the instantaneous acceleration.

That's my problem: I don't know how to get the instantaneous acceleration. At 44.17 mph the time is at 19 s. Should I create a derivative. If so, how do I go about it?

The answer for this problem is 764 N

Please tell me why my approach is incorrect.

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# Force due to wind and rolling friction on van

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