- #1
That_EDGEy_KiD
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Homework Statement
Block A has a mass of 3 kg, and block B has a mass of 8 kg. Determine the speed of block A if it moves upwards 2 meters, starting from rest. I can solve the problem pretty easily if the mass and radius of each of the pulleys is neglected. However, if they are not neglected and let's say that the question provides a known mass and radius for each of the top and bottom pulleys, how would I still go about solving for the velocity of block A?
Homework Equations
KE = (1/2)mv^2
g = 9.8 m/s^2
The Attempt at a Solution
Neglecting the mass/radius of the pulleys,
(1/2)mAvA^2 + (1/2)mB(2vB)^2 = mBg(4) - mAg(2)
=> 17.5vA^2 = (8x4 - 3x2)g
=> 17.5vA^2 = 26g
=> vA = 3.82 m/s
However, If the top pulley had a mass of say 0.50 kg with a radius of 0.10 m and the bottom pulley had a mass of say 0.40 kg with a radius of 0.5 m, how would I solve for the velocity of block A since now the tensions are all different?