An object of mass 1 kg is droppex from a height of 10 m
Answers
Answer:
What would you like to ask?
11th
Physics
Laws of Motion
Newton's Second Law of Motion
An object of mass 1 kg is d...
PHYSICS
avatar
Asked on October 15, 2019 by
Anudeep Sheik
An object of mass 1 kg is dropped from a height of 20 m. It hits the ground and rebounds with the same speed. Find the change in momentum. (Take g=10 m/s
2
)
MEDIUM
Share
Study later
ANSWER
mass, m = 1kg
height, s = 20m
initial velocity of ball, u = 0m/s
acceleration, a = 10m/s
2
Using, v
2
= u
2
+ 2as
= 0 + 2×10 ×20
= 400
v = 20m/s
Now, let us take upward direction as positive and downward direction as negative.
Initial momentum of the ball (before striking the ground) = m×v
= 1×(-20) (velocity is downward, hence negative)
= -20kgm/s
Now, when the ball strikes and rebounds, its velocity becomes +20m/s (after striking, it moves upward, hence positive velocity)
Final momentum (after striking the ground) = m×v
= 1×(+20)
= +20kgm/s
Change in momentum = Final momentum - Initial momentum
= 20kgm/s - (-20kgm/s)
= 40kgm/s in upward direction.
Explanation: