Friction

What is the minimum value of the resultant force S when there is no friction?

mg (correct)
2mg
mg/2
mg/4

What is the angle of repose of an inclined plane with a coefficient of friction 1/3?

90°
45°
60°
30° (correct)

What is the relationship between the angle of friction and the angle of repose?

α = 3θ
α = θ (correct)
α = 2θ
α = θ/2

What happens to the resultant force S when the coefficient of friction μ increases?

S increases (A) Signup and view all the answers

What is the condition for a body to start sliding on an inclined plane?

F = mg sin α (D) Signup and view all the answers

What is the coefficient of friction represented by?

$\mu = 2tan \theta$ (D) Signup and view all the answers

What is the minimum pulling force required to move a body up an inclined plane?

$P = W sin(\theta - \lambda) cos(\alpha - \theta)$ (B) Signup and view all the answers

What is the minimum force required to avoid sliding a body down an inclined plane?

$P = \frac{W sin(\lambda - \theta)}{cos(\alpha - \theta)}$ (D) Signup and view all the answers

What is the angle of friction?

The angle at which the body starts sliding down an inclined plane (D) Signup and view all the answers

What is the resultant force on a body on an inclined plane?

The sum of the horizontal and vertical components of the force (C) Signup and view all the answers

What is the coefficient of friction between a body and a wedge when the body takes twice the time to slide down a plane inclined at 30° to the horizontal?

1/2 (D) Signup and view all the answers

If a body slides on a smooth wedge of angle θ, what is the acceleration of the body?

g sin θ (A) Signup and view all the answers

What is the effect of increasing the angle of friction on the motion of a body on a plane?

It decreases the speed of the body (D) Signup and view all the answers

What is the resultant force acting on a body on a plane inclined at an angle θ to the horizontal?

mg sin θ (D) Signup and view all the answers

What is the angle of repose for a body on a plane when the frictional force is equal to the component of the weight down the plane?

tan^-1 μ (C) Signup and view all the answers

What is the maximum force of friction available at the point of contact between the ladder and the floor?

75 N (C) Signup and view all the answers

What would happen to a body placed in a vehicle that is accelerating if there were no friction between the body and the vehicle?

The body would remain at rest in the accelerating vehicle (D) Signup and view all the answers

Why is friction necessary for a body to start moving?

Because friction provides the force to accelerate the body (D) Signup and view all the answers

What is the coefficient of friction between the ladder and the floor?

0.3 (D) Signup and view all the answers

What would happen to the force of friction on the ladder if the normal force exerted by the ladder on the floor were to increase?

The force of friction would increase (A) Signup and view all the answers

What is the primary reason for the reduction in efficiency of machines due to friction?

Extra energy is spent in overcoming friction (C) Signup and view all the answers

What is the purpose of lubrication in machines?

To reduce friction and increase efficiency (D) Signup and view all the answers

What is the relationship between the angle of friction and the coefficient of limiting friction?

The coefficient of friction is equal to the tangent of the angle of friction (A) Signup and view all the answers

Why is synthetic rubber preferred in the manufacturing of tires?

Because it has a higher coefficient of friction with the road (B) Signup and view all the answers

What is the effect of increasing the coefficient of friction on the motion of a body on an inclined plane?

The body will slide down the plane more slowly (C) Signup and view all the answers

What is the maximum horizontal force on B to make both A and B move together in the first problem?

36 N (B) Signup and view all the answers

What is the minimum force required to make B slide on A in the second problem?

1.764 N (B) Signup and view all the answers