A force of 20 N applied parallel to the surface of a horizontal table, is just sufficient to make a block of mass 4kg move on the table. Calculate the coeff...
A force of 20 N applied parallel to the surface of a horizontal table, is just sufficient to make a block of mass 4kg move on the table. Calculate the coefficient of friction between the block and the table. (g = 10ms2)
Answer Details
The force applied parallel to the surface of the table is the maximum force of friction between the block and the table that is just sufficient to make the block move on the table.
The frictional force (f) acting on the block is given by the product of the coefficient of friction (μ) and the normal force (N) acting on the block.
Therefore, we can write:
f = μN
where N = mg is the normal force on the block due to the gravitational force acting on it.
Since the block is just about to move, the force applied (20N) is equal to the maximum force of friction, i.e.,
f = 20N
Substituting the values of N and f in the equation f = μN, we get:
20 = μ × 4 × 10
Solving for μ, we get:
μ = 20/40
μ = 0.5
Therefore, the coefficient of friction between the block and the table is 0.5.
Hence, the correct option is (c) 0.50.