Question
Question: The two blocks, m = 10kg and M = 50kg are free to move as shown. The coefficient of static friction ...
The two blocks, m = 10kg and M = 50kg are free to move as shown. The coefficient of static friction between the blocks is 0.5 and there is no friction between M and the ground. A minimum horizontal force F is applied to hold m against M that is equal to:
A
100 N
B
50 N
C
240 N
D
180 N
Answer
240 N
Explanation
Solution
As m would slip in vertically downward direction, then to prevent slipping by applying minimum force
mg = μN
⇒ N = mg/μ = 100/.5 = 200 N
Same normal force would accelerate M, thus
aM = 200/50 = 4 m/s2
Taking m + M as system
F = (m + M). aM = 240 N