Question

The block shown in the diagram has no forces acting on it other than those shown. If the block is moving to the right at a constant velocity, how do the forces $F_{left}$ and $F_{right}$ compare to each other?

• A. $F_{left}$ is less than $F_{right}$
• B. $F_{left}$ is equal to $F_{right}$
• C. $F_{left}$ is greater than $F_{right}$
• D. This question cannot be answered without knowing the exact velocity of the block

Answer 1

Answer: (B)

$F_{left}$ is equal to $F_{right}$

As the block is moving with constant velocity in horizontal direction, thus net external force acting on the block in horizontal direction must be zero.

$\therefore$ $F_{right}-F_{left}=0$ $⟹F_{left}=F_{right}$