a girl of mass 48 kg is rescued from a building fire by leaping into a fire fighters net.The window from which she leapt was 12m above the net. She lands in the net so that she is brought to a complete stop in 0.45s. During this interval (a) Find his change in momentum. (b) What is the impulse on the net due to the girl? (c) What is the average force on the net due to the girl?
Answers
ANSWER:
Momentum by taking g=10m/s^2
216 kgm/s
Momentum by taking g=9.8m/s^2
211.68 kgm/s
Answer:
The correct answer is 216 kgm/s by taking Momentum g = 10m/s² and 211.68 kgm/s with Momentum g = 9.8m/s².
Explanation:
We know that p = mv and mass m is 48 kg.
Solution considering Momentum g = 9.8m/s²
p = 48 × (9.8 × 0.45)
= 48 × 4.41
= 211.68 kgm/s
Solution considering Momentum g = 10m/s²
p = 48 × (10 × 0.45)
= 48 × 4.5
= 216 kgm/s
The impulse is equal to the rate of change of momentum. The impulse-momentum theorem explains how impulse and momentum are related. It is stated as the shift in momentum Δp=Δ(mv). Either a change in the body's mass or its velocity can result in a change in momentum. A body's change in momentum is defined as a change in the body's product of mass and velocity. Momentum is the product of the amount of motion, the volume of the stuff moved, and the speed at which it moves.
Thus, if a body experiences no external forces at all, then there is no momentum change because the rate of momentum change is likewise zero.