Question

A block of mass m is initially at rest on a rough horizontal surface when a constant force f is exerted on it, as shown. The block accelerates to the right and is moving with speed v once it has moved a distance d. Which of the following equations can be used to solve for the force of friction exerted on the block by the surface?.

Answer 1

R = ma - f

Step-by-step explanation:

The forward force on the block is f.

the backwards resistive force on the block is frictional force (let it be R).

the resultant force due to these two forces is mass × acceleration , as F= ma

so, forward force - friction force = resultant force

f - R = ma

R = ma - f

options were missing, but thus is one way we can figure out the force of friction.