What is the differece between impulse and change in momentum?

Question

What is the differece between impulse and change in momentum?
I thought they were the same but the notes that I read say that we use impulse= F(net) x time while change in momentum= mass x change in velocity.

Why can't we use the other formula to find the other one like use the momentum formula to find impulse? How can we?

Question:
A boy of mass 60kg is rescued from a hotel fire by leaping into a firefighters' net. The window from which he leapt was 8.0m above the net. The firefighters lower their arms as he lands in the net so that he is borught to a complete stop in a time of 0.40s.

(a) What is his change in momentum during the 0.40s interval?
v^2= u^2 +2as
v^2= 2(9.81)(8) , taking downwards as positive
v=12.5m/s
change in momentum= m(change in velocity)
= (60)(12.5-0)
= 752 kgm/s

(b) What is the impulse on the net due to the boy during the interval?
How do you find this before finding

Answer 1

Impulse is related to change of momentum in that an impulse may result in a change of momentum.

They are not identicallly the same thing, since a particles momentum may be changed due to other reasons, such as a collision.



In your example,

his momentum at hte time he hit the net was 751.7 kg m/s as you showed.

His momentum afterward was 0.

So his change of momentum was -751.7 kg m/s.

Don't forget that negative sign. Momentum is a vector.



The impulse on the net in this case is the same value 751.7 Ns. Ns and kg m/s are the same, but Ns is usually used for impulse.

By the law of conservation of momentum, all his momentum is absorbed by the net, resulting in the impulse exerted on the net.



The average force onthe net is impulse / time = 1879.3 N. It is positive since hte net is gaining momentum.

The force on the boy BY hte net is negative, since it is slowing him down.

Answer 2

Impulse The exchange in momentum is named the impulse and is given the physics code Dp. we are able to define Newton’s 2nd regulation in terms of exchange of momentum: stress = exchange in momentum __________________ term Þ Impulse (Ns) = stress (N) x term (s) In code: Dp = FDt Momentum is the product between mass and velocity. Being a vector volume, it has a path, and the path is fairly significant whilst doing momentum calculations. Momentum isn't a ingredient that we are able to be certain, besides the undeniable fact that it does clarify many stuff that pass on in physics. Momentum (kg m/s) = mass (kg) x velocity (m/s) contraptions are kilogram metres in keeping with 2nd (kg m/s) or newton seconds (Ns). we are able to tutor that the contraptions are the comparable.

Answer 3

when a force acts on a bodyfor some duration of time,it gives impulse to the body which produces the change in momentum in the body, the two being equal.