Chapter 7, Problem 56A

What is the net force on a falling 100-N barrel hitting a pavement with 5000 N of force?

To determine

Net force on the falling barrel.

Answer to Problem 56A

F = 4900 N upward.

Explanation of Solution

Given:

Weight of barrel, $W=100\text{N}$

Impulsive force on heating, 5000 N

Formula Used:

From Newton’s third law,

Action force = Reaction force

Calculation:

From Newton’s third law,

The reaction force exerted by pavement on the barrel is 5000 N upward and the weight of barrel is downward.

So,Net force F = Force exerted by pavement on barrel − Weight of barrel

  $\begin{array}{l}F=5000-100\\ =4900\text{N}\end{array}$

This force will be upward.

Conclusion:

Therefore, the net force on the falling barrel is 4900 N upward.