Mass m1 = 11.7 kg is on a horizontal surface. Mass m2 = 8.71 kg hangs freely on
ID: 2179112 • Letter: M
Question
Mass m1 = 11.7 kg is on a horizontal surface. Mass m2 = 8.71 kg hangs freely on a rope which is attached to the first mass. The coefficient of static friction between m1 and the horizontal surface is ?s = 0.493, while the coefficient of kinetic friction is ?k = 0.144.
A)If the system is in motion with m1moving to the left, then what will be the magnitude of the system's acceleration? Consider the pulley to be massless and frictionless.
I found this answer to be 5.00 m/s^2 and it is correct
B) I really need help with this one.
If the system is in motion with m1moving to the right, then what will be the magnitude of the system's acceleration?
Explanation / Answer
m2g - T = m2a
T -km1g = m1a
eliminating T
a = (m2-km1)g /(m1+m2)
= (8.71 - (0.144*11.7))*9.81/(11.7+8.71) = 3.376 m/s2