Question

A ball of mass 20g is moving with a velocity of 25ms^-1 on applying a constant force on the ball for 4 seconds it acquires a velocity of 80ms^-1 . Another ball of mass 80g is moving with an initial velocity of 50ms^-1. Calculate the rate of change of momentum of 1st ball and compare inertia of the balls which ball has greater initial momentum

Answer 1

ANSWER


mass of the ball (m) =100g or 0.1kg
initial velocity (u) =25sm​
time (t) = 0.025sec.
final velocity (v) = 0

Initial momentum = mu

                              = 0.1×25​
                               = 2.5 skgm​

Final momentum = mv (which is equal to 0, since v is zero)

Change in momentum = mv-mu

                                               = 0 - 2.5 = -2.5 skgm​

Average force = timeChangeinmomentum​


                                  = - 0.025(2.5)​ 


                               = -100skgm​
                                 = -100 N

The negative sign actually shows that the force was applied

 opposite to the direction of the motion of the ball. 

So, the average force  applied by the player will be 100 

Answer 2

Answer:

mass of the ball (m) =100g or 0.1kg

initial velocity (u) =25

s

m

time (t) = 0.025sec.

final velocity (v) = 0

Initial momentum = mu

= 0.1×25

= 2.5

s

kgm

Final momentum = mv (which is equal to 0, since v is zero)

Change in momentum = mv-mu

= 0 - 2.5 = -2.5

s

kgm

Average force =

time

Changeinmomentum

= -

0.025

(2.5)

= -100

s

kgm

= -100 N

The negative sign actually shows that the force was applied

opposite to the direction of the motion of the ball.

So, the average force applied by the player will be 100