# How do you use percent-error calculations to find the force of friction?

Hey, here's an example of a percent error calculation: Hanging Mass = 500g Applied Force: (9.8)(0.5) = 4.9N Mass of cart + extra masses: 988.5 Mass of cart: 488.5g Theoretical Acceleration = 3.29 m/s2 Average Experimental Acceleration = 3.152 m/s2 % Difference = (Theoretical - Actual)/ theoretical ... show more Hey, here's an example of a percent error calculation:

Hanging Mass = 500g
Applied Force: (9.8)(0.5) = 4.9N
Mass of cart + extra masses: 988.5
Mass of cart: 488.5g
Theoretical Acceleration = 3.29 m/s2
Average Experimental Acceleration = 3.152 m/s2
% Difference = (Theoretical - Actual)/ theoretical
= (3.29-3.512)/3.29
= 0.0426
= 4.26%

How do I use this value to find the force of friction?

(Basically the lab is where we put weights on a cart, attach it to string, and put the string through a pulley with weights on it, so the only thing driving the cart is the force of gravity of the weights on the string....)