Question

You apply a $75-N$ force to pull a child's wagon across the floor at a constant speed $0.5m/s$. If you increase your pull to $90N$, the wagon will then

• A. Continue to move at $0.5m/s$
• B. Speed up immediately and then move at the faster constant speed of $0.6m/s$
• C. Speed up gradually until it reaches the speed of $0.6m/s$ and then move at that constant speed
• D. Continue to speed up as long as you keep pulling
• E. Do none of the above

Answer 1

The correct option is D Continue to speed up as long as you keep pulling

Given,

Previously force is $75N$, but velocity is constant.

Therefore, initial acceleration is constant.

But, when force increase to $90N$

Net force, $F_{net}=90-75=15N$

Hence, continue to speed up as long as you keep pulling.