# Physics - application of Momentum

posted by .

Try to imagine a situation in which the form f=ma would no apply, but the form f=delta p / delta t could be used. Describe that situation. How could you test your prediction.

• Physics - application of Momentum -

Could this be a possible answer for the above question.

When catching a ball with bare hands hurts, because it has some force. Since the the ball will always approach one at the same speed, therefore its change in momentum deltaP= Vfinal - Vinitital where Vfinal is zero.
Thus if you allow your hands to move in with the ball as you catch it, you increase the contact time and the total force will be less and hurts less on bare hands.

• Physics - application of Momentum -

Since p = mv,

f = dp/dt is equivalent to f = m dv/dt = ma, if the mass is constant

However, mass IS constant for a closed system; so I can't imagine situation with f not equal to m*a.

• Physics - application of Momentum -

Total force required to catch a ball is indeed less if you decelerate slowly with a longer contact time. But you have decreased a to decrease f.

f still equals m a

• Physics - application of Momentum -

Could the question be true when the mass is not constant, say maybe in the case of cars.

When two cars collide, their masses change but their resultant momentum would be the same before and after the crash so you could you delta p, and the time.

Would that be a possible answer?

## Similar Questions

1. ### equibrium - help!

Consider the reaction CO(g) + H2O(g) <--> CO2(g) + H2(g) Use the appropriate tables to calculate a) delta-G*f at 552*C b) K at 552*C I'm pretty sure I have a good idea of how to do this: I believe I can use Gibbs-Helmholtz equation …
2. ### Chemistry

Clapeyron equation: dp/dT = ΔS / ΔV My textbook says, for fusion/melting reactions: dp/dT = ΔH / (T ΔV) this implies that T * ΔS = ΔH. I know T * ΔS = q and at constant pressure, that equals …
3. ### Physics

1. If the change in position delta(x) is related to velocity v (w/ units of m/s) in the equation delta(x)=Av, the constant A has which dimension?
4. ### Physics

momentum equals = mass (velocity) yet for problems I end up using this P = m (delta v) what allows us to simply put the delta infront of the v to find the momentum?
5. ### Physics

I agree with this and see were it comes from net force = (delta p)/t so momentum is conserved when net force equals zero... net force = (delta p)/t 0 = (delta p)/t however the following is not true 0 = (delta p)/t = P - Po were p is …
6. ### Physics

h t t p : / / i m g 2 0 5 . i m a g e s h a c k . u s / i / c a p t u r e b b . j p g / i am stuck on part c how do i find work with out using the spring constant work equals force parallel times displacement at which the force is …
7. ### Physics - Momentum

Try to imagine a situation in which the form f=ma would no apply, but the form f=delta p / delta t could be used. Describe that situation. How could you test your prediction.