Question

Twopucksofequalmasscollideonafrictionlesssurface,asillustratedinthefigure.Immediatelyafterthe collision, the speed of the black puck is 1.5 m/s. What is the speed of the white puck immediately after the collision?

Answer 1

Answer:

The speed of the white puck immediately after the collision is 2.6 m/s.

Explanation:

Given that,

Two pucks are equal masses.

Speed of black puck = 1.5 m/s

According to given figure,

We need to calculate the speed of the white puck immediately after the collision

Using law of conservation of momentum

$mv=m_{1}v_{1}\cos\theta+m_{2}v_{2}\cos\theta$

Put the value into the formula according to figure

$m\times3=m\times v_{1}\times\cos30+m\times1.5\times\cos60$

$3m=0.866m v_{1}+0.75m$

$v_{1}=\dfrac{3-0.75}{0.866}$

$v_{1}=2.6\ m/s$

Hence, The speed of the white puck immediately after the collision is 2.6 m/s.