Question

A 50kg crate rests on the floor. The coefficient of static friction is 0.5. The force parallel to the floor needed to move the crate is most nearly:

• A. 25 N
• B. 50 N
• C. 125 N
• D. 250 N
• E. 500 N

Answer 1

The correct option is D 250 N

The force needed to move the crate is equal and opposite to the maximum force of static friction $F_s={\mu }_{s}mg$,
where ${\mu }_s$ is the coefficient of static friction.
Therefore, the magnitude of the force parallel to the floor is
$F={\mu }_{s}mg=\left(0.5\right)\left(50kg\right)\left(10m/s^2\right)$
$F=250N$