Question

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

Answer 1

Answer:

B

Explanation:

momentum = mass * velocity

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

Answer 2

Answer:B

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