Recent content by Ivar

Must i find the speed with no Air resistance, calculate with the same equation and subtract the first answer from my second one? Which, to hope, will give me an answer of -4,6 Joule?

Well, that would be the 1/2v^2*mgh=1/2V(0)^2*mgh(0), would it not? How does that help me calculate the resistance of the air?

I did this:Wa=1/2*0.2*11^2 + 0.2*9.81*8.5 - 1/2*0.2*0^2 = 12.1+16.67=28,77 The answer should be -4.6Joule How do I Get there?

Homework Statement Hey! Problem: A ball falls 8,5 meters, and hits the ground with 11 m/s. The ball has a mass of 0,2 kilos. How much work was done by Air resistance on the ball? Homework Equations I guess mechanical energy eqution? The Attempt at a Solution answer should be -4,5 joule...

Yes. That I know. Bit how does this help me find the height of the Slope? And what is the accelleration of an object running down a slope with no friction?

Homework Statement A box is on top of a slope. The slope has NO FRICTION. V0 = 0 m/s, V = 4m/s. MASS IS UNKNOWN What is the height of the slope? Homework Equations Equation for energy (i think)The Attempt at a Solution I attempted to find the accelleration, but I do not know what the...