# How much momentum will a dumb-bell of mass 10kg transfer to the floor if it falls a height of 80 cm? Take its downward acceleration to be 10 m//s

39 views
in Physics
closed
How much momentum will a dumb-bell of mass 10kg transfer to the floor if it falls a height of 80 cm? Take its downward acceleration to be 10 m//s^(2).

by (66.1k points)
selected by

Mass of the dumbbell, m = 10 kg
Distance covered by the dumbbell, s = 80 cm = 0.8 m
Acceleration in the downward direction, a = 10 m//s^(2) 
Initial velocity of the dumbbell, u = 0
Final velocity of the dumbbell (when it was about to hit the floor) = v
According to the third equation of motion:
v^(2)= u^(2) + 2as
v^(2)= 0 + 2 (10) 0.8 
v= 4 m/s
Hence, the momentum with which the dumbbell hits the floor is
= mv  = 10 xx 4 kg ms^(-1)
= 40 kg ms^(-1)`