Question

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

Answer 1

4900 N

Explanation:

At the moment when the barrel hits the pavement, there are two forces acting on the object:

- its weight (force of gravity), pointing downward, of magnitude 100 N

- the reaction force (Newton's third law) exerted by the pavement on the barrel, pointing upward and of magnitude 5000 N (this is equal and opposite to the force exerted by the barrel on the pavement, which is also 5000 N)

Therefore, the net force on the barrel is:

$F=5000 N-100 N=4900 N$

Answer 2

Answer:

The net force on the barrel will be 4900N in the upward direction.

Explanation:

According to Newton’s third law of motion:  

“Action and reaction forces are equal but opposite in direction”.  

So, when the barrel hits the pavement with 5000N then pavement exerts 5000N force in the upward direction. Weight of the barrel is 100N which will be subtracted from the 5000N as shown below:  

Net force = F = Force exerted by pavement on barrel – Weight of barrel

Net force = F = 5000 – 100

Net force = F = 4900N  in upward direction