Question

The two blocks, m = 10 kg 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 ______.

Options

• 100 N

• 50 N

• 240 N

• 180 N

Answer 1

The two blocks, m = 10 kg 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 240 N.

Explanation:

As m would slip in vertically downward direction, then

mg = μN

⇒ N = `"mg"/mu=100/0.5`

= 200 Newton

Same normal force accelerated M,

thus a_M = `200/50` = 4 m/s²

Takin (m + M) as system

F = (m + M)4 = 240 N