Question

Three children are pushing a block on a smooth surface towards the right with equal forces of 15 N. Their father is also pushing the same block with a force of 45 N towards the left as shown. Calculate the net force acting on the block.

• A. 90 N
• B. 0 N
• C. 15 N
• D. 45 N

Answer 1

The correct option is B 0 N

The forces applied by the children are in the same direction. Therefore, they will be added together to get the resultant force acting from left to right.

So, the total force exerted by the children, $F_1=15+15+15=45N$
The force applied by their father, $F_2=45$
Net force, $F=F_1-F_2=45-45=0N$