- #1
Lawcheehung
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Homework Statement
Basically there's a 1.00 kg object hanging in the air attached to a string which is attached to a 0.1487 kg object that is on a table, and they're connected with a pulley.
the 1.00 kg object pulls the 0.1487 kg a distance of 0.89 m in 1.22 s and then stops when it hits the ground, i need to find the coefficient of friction
ok so..
first i found the final velocity of the object
which is 0.89 m / 1.22 s which gave me a final velocity of 0.7295 m/s
then i found the acceleration of the entire body by doing
a = (vf - vi)/t which gave me an acceleration of 0.597957 m/s^2
The Fnet of the entire body is
Fnet = [(0.100kg ) + (0.1487kg )] * (0.597957 m/s^2)
= 0.14871 N
This is the actual net force with the friction
so the acceleration of the 0.100 kg falling down without the tension should be just
mg = (0.100)(9.8)
= 0.98 N
so the friction force should be
0.98 N - 0.14871 N
= 0.83129 N
This is the friction force.
The coefficient of friction is
Ff = uFn
so 0.83129 N = u(mg)
0.83129 N = u(0.1487 kg * 9.8 m/s^2)
u = 0.5704
Please i need help URGENT