/diy/ - Do It Yourself

>>600533
>Yes but force is zero when car is travelling at constant velocity?

Net Force = (Force from motor) - (Force of friction)

Typically you use Net Force when calculating work, but that's going to be zero for a vehicle traveling at constant speed on a level surface. If you project requires finding a % efficiency just be sleezy and use (Force of motor) for F int he equation. Make note of it in your presentation or paper or whatever.

I slightly less sleazy solution would be to drag a mass behind you. The mass should have an approximately constant drag once you get it moving. You can measure this whit a newton meter. It takes more force to get it moving than it does to keep it moving. The force of drag is material dependent, so your track will have to be all the same material, and you'll have to measure the drag by pulling the weight around on that material with a newton meter.

That would make the math much simper.