Question

A box of mass $100kg$ rests on the floor. A horizontal force $344N$ is applied to the box. Assume the coefficient of static friction between box and the floor is $0.5$ and coefficient of kinetic friction is $0.4$. Which of the following statement is true?

• A. The box will accelerate across the floor at $0.5m/s^2$.
• B. The static friction force, which is the reaction force to $F$ as guaranteed by Newton's third law, will also have a magnitude of $344N$.
• C. The box will slide across the floor at a constant speed of $0.5m/s$.
• D. The box will not move
• E. None of the above

Answer 1

Answer: (D)

The box will not move

The maximum value of the static friction possible$={\mu }_{s}mg=0.5\times 100\times 10=500N>344N$

Thus the static friction would adjust to $344N$ and would not allow the box to move at all.