Find the correct value:
 
A ball of mass \(3\ kg\) moving with a speed of \(20\ ms^{-1}\) rebounds after a perfect elastic collision with the floor. Calculate the change in linear momentum of the ball.
 
Mass of a ball (\(m\)) \(=\) \(kg\)

Velocity of the ball before collision (\(u\)) \(=\)  \(ms^{-1}\)
 
Velocity of the ball after collision (\(v\)) \(=\) \(-\) \(ms^{-1}\)
 
The formula to calculate the change in linear momentum is
 
Δp=i×(ii)
 
On substituting the known values, we get
 
Change in linear momentum of the ball \(=\) \(-\)  \(kg\ ms^{-1}\)