A block of mass 5 kg is placed on a rough horizontal surface with a coefficient of static friction 0.4. A horizontal force of 20 N is applied to the block. What is the frictional force acting on the block?

A. 20 N — The maximum static friction is calculated as f_max = mu * m * g, which equals 0.4 * 5 * 10 = 20 N. Since the applied force is exactly equal to the maximum static friction, the block is on the verge of sliding and the frictional force is equal to the applied force.

JEE Main · PhysicsMedium

$A block of mass m = 5 kg is placed on a rough horizontal surface with a coefficient of static friction μ_{s} = 0.4 . A horizontal force of F = 20 N is applied to the block. What is the frictional force f acting on the block? (Take g = 10 m/s^{2})$

A. $20 N$
B. $10 N$
C. $15 N$
D. $0 N$

Show correct answer & step-by-step solution

Correct answer: A — $20 N$

Solution

The maximum static friction is f_{max} = μ_{s} m g = 0.4 \times 5 \times 10 = 20 N . Since the applied force F = 20 N is equal to f_{max}, the block is on the verge of sliding and the frictional force is equal to the applied force.

Attempt this question & track your score

Attempt & Track Free →

More Laws of Motion practice questions

$A force of 10 N acts on a body of mass 2 kg. What is the acceleration produced in the body?$
$Which of the following is a measure of the inertia of a body?$
$A rocket works on the principle of conservation of which physical quantity?$
$If a body is moving with constant velocity, what is the net external force acting on it?$
$An impulse is equal to the change in which quantity?$
$A block of mass 5 kg is placed on a rough horizontal surface with coefficient of static friction 0.4. A horizontal force$
$A body of mass 2 kg is moving along the x-axis with a velocity of 4 m/s. A force of 6 N is applied in the negative x-dir$
$Two blocks of masses 3 kg and 2 kg are connected by a light string passing over a frictionless pulley. The system is rel$
$A rocket of initial mass 1000 kg ejects gas at a rate of 20 kg/s with a velocity of 500 m/s relative to the rocket. What$
$A particle of mass 0.5 kg is moving in a circle of radius 2 m with a constant speed of 4 m/s. What is the net force acti$
$A block of mass m is placed on a wedge of mass M and angle theta. The wedge is placed on a smooth horizontal surface. If$
$A particle of mass m moves along a circle of radius R with a constant speed v. What is the average force exerted on the$

View all Laws of Motion questions →

A block of mass m=5 kg is placed on a rough horizontal surface with a coefficient of static friction μs​=0.4. A horizontal force of F=20 N is applied to the block. What is the frictional force f acting on the block? (Take g=10 m/s2)

Solution

Attempt this question & track your score

More Laws of Motion practice questions

$A block of mass m = 5 kg is placed on a rough horizontal surface with a coefficient of static friction μ_{s} = 0.4 . A horizontal force of F = 20 N is applied to the block. What is the frictional force f acting on the block? (Take g = 10 m/s^{2})$