Question

Since force depends on mass and acceleration, does that mean that if you drop a brick onto concrete from ANY height, the concrete and brick will experience the same force regardless of height dropped (disregarding air friction). That seems misleading...

Answer 1

yes cause the formula is independent of height so the force must be equal???

Answer 2

The forces would be different for different heights, but same for the brick and concrete for either case from the Newton's second law of motion.

Answer 3

But how can the force be different? The force must be equal since at all points in time the brick is experiencing the same acceleration. I know that the force must be equalat all points, what I don't get is why, then, it is not the same to drop a brick 1 meter than from 100 meters.

Answer 4

Try it out, throw a brick down from 1m and then throw it down from 100m roughly. Observe what happens to the brick.

Answer 5

I don't have a brick handy.... But I do know that the brick will "break apart" much more if it is droppedfrom a higher height. But, according to convetional knowledge, the brick is expieriencing the same force regardless of height. What is different at different heights is kinetic energy and momentum.

So does the brick being dropped from a taller height absorb more energy and hence it flys apart more, while still experiencing the same force? That seems misleading, that there is the same net force, yet different amounts of energy absorbed.

Answer 6

Looks like confusion there. But dont ignore the fact that the brick will break apart. I believe it has to do with gravitational heights. I'm at no point on proving this mathematically but will search it for you.

Answer 7

@DeoxNA ,you are right that the force will be same because of acceleration is same.
But the here time is taken by brick to come on the concrete,because of it drops from different height, hence the impulse(Force* time) is different here. so when the brick drops onto concrete it experiences different force.. because of impulse is different here. and we know that the rate of change in impulse , also gives a Force.Hence the force must be differ after collision with concrete.

Answer 8

But lets say that the bri
ck weighs 1 kg and gravity is 10 m/s´2. using the formula s=(1/2)at´2, you get that the brick takes root 2 seconds to drop 10 m and root 20 seconds to drop 100 meters. So you multiply these values by the force of gravity 10 N, and you get different impulses. Then, to find the force (impulse/time) you divide time again and get 10 N for both cases regardles....

Am I missing something?

Answer 9

@DeoxNA,this time is not that time this is collision time between brick and concrete.any confusion.....

Answer 10

Oh ok, and would this collision time be about the same in both cases, just fractions apart maybe?

Answer 11

yes ....