Lab report: pulling cart up a ramp, find efficiencies

[msimard8]

I am doing a lab report and something is wrong. I don't know if it is my results, or if it is my calculation.

What we did was pull a cart up a ramp upside down (wheels facing up) with different masses and different angles of the ramp. We pulled it up with a spring scale calibrated in Newtons. The Newtons were recorded and the height, distance, and angle of the ramp were in this chart. The sigificant digits are off but that shouldn't affect the results I am getting. The efficiencies are way over 100% which is maximum.

Formulas that I used are

Total Energy Input = force x distance
Useful Energy Output = mass x gravitational energy x height
Efficency = Energy output/ energy input x 100%



The chart is not complete yet though.

 

[Chi Meson]

Total Energy Input = force x distance
Useful Energy Output = mass x gravitational energy x height
Efficency = Energy output/ energy input x 100%

I have to fix your words here-- this should read:

total work input = force x distance
useful work output = mass x gravitational field strength x height


I haven't seen the chart yet (approval is pending) but let me take a few stabs:
did you include the mass of the cart itself? (you should have)
did you multiply the weight of the cart (in Newtons) times "g"? (you should NOT have)
did you convert grams to kilograms correctly? (200 g = 0.200 kg)

 

[msimard8]

thanks

problem solved