Question

A block sliding down a fixed inclined plane slows to a stop. Which of the following is true?

A. A change in the normal force caused the block to stop.

B. The kinetic friction force was less than the component of the weight down the inclined plane.

C. The kinetic friction force was greater than the component of the weight down the inclined plane.

D. The static friction force overcame the kinetic friction force.

Answer 1

A block sliding down a fixed inclined plane slows to a stop.

Which of the following is true?

$\Rightarrow$ A change in the normal force caused the block to stop.

option (A) : it will be correct.

Explanation - If block slides down a frictionless plane inclined at an angle $\theta$, the acceleration down a plane is g sin because the component of g (the downward acceleration due to gravity) that points along the plane is g sin $\theta$.

There is no acceleration perpendicular to the plane because the normal force from a plane cancels the component of gravitational force which perpendicular to the plane.

gsin θ g sin 9