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A 2.5 kg stone is released from rest and falls toward Earth. After 4.0 s, magnitude of its momentum in kg.m/s is :

A-78
B-98
C-122.5
D-24.7

User Jayesef
by
5.8k points

2 Answers

2 votes

Answer:

B

Step-by-step explanation:

momentum = mass * velocity

velocity = initial speed + acceleration * time where initial speed =0, acceleration = 9.81, time = 4

User Mirjalol Bahodirov
by
6.8k points
3 votes

Answer:B

Step-by-step explanation:

Initial velocity(u)=0

Time(t)=4seconds

Mass(m)=2.5kg

acceleration due to gravity(g)=9.8m/s^2

Final velocity(v)=u+gxt

Final velocity(v)=0+9.8x4

Final velocity(v)=39.2m/s

Momentum=mass x velocity

Momentum=2.5 x 39.2

Momentum=98kgm/s

User Tejas N
by
5.8k points