# What is the work produced from friction in an inclined ramp.?

I just need to know the the friction.

In this topic I was learning about forces in angles so i guess knowing what my forces are is important?

In the experiment we did, we used the one light gate to only measure the velocity.

I was confused and my teacher isn't helping and he gets pissed when I can't work out how he did it.

I got something like acceleration in X direciton is   g(the acceleration of free fall)*sin(theta)

They don't give you any values btw. Anyone please help ASAP! I do not want to be killed by my teacher

Update:

sorry i dont need to know the friction, just read the task I just can't explain hard enough Relevance

Eff = (mgh - Ff*d)/mgh

The friction opposing motion = m*g*µ*cosΘ

The work done by friction = Ff*d

But h = d*sinΘ

Ff*d = (m*g*µ*cosΘ)*d

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• If cart starts h above light gate and measured speed is v

With no loss of mechanical energy, you'd have mgh = mv^2 / 2

With, the energy lost is m(v^2 / 2 - gh)

Efficiency is the percent of energy that remains. v^2 / (2gh)

Acceleration is g(sinθ - µcosθ). You have friction triplequestionmark. Irrelevant anyway.

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• If the cart is at rest at the top of the ramp then the only energy it possesses is the gravitational potential energy, PE = mgh

where m=mass of the cart and h = height of the ramp from where the cart is released

Now when you release the cart you measure the time it takes to cross the light gate.

And you know the distance from where the cart was released until the distance where the light gate is located. Using that distance on the slope and the time from light gate you find the velocity v

Considering the light gate is at the bottom of the ramp, the only energy that it possess will be the kinetic energy, KE = ½mv²

Ideally if the ram was frictionless all that potential energy would have been converted to Kinetic energy. But since the ramp has friction we find the waste in energy due to friction as

Energy lost due to friction = PE - KE = mgh - ½mv² = m(gh - ½v²)  Joules

Average efficiency of the car = Actual energy used / Energy originally available

Average efficiency of the car = ½mv²/(mgh)

Average efficiency of the car = v²/(2gh)

In terms of percentage it will be v²/(2gh) x 100%

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