Billiard ball 1, moving at speed 2m/s, strikes billiard ball 2 (initially at res

Question

Billiard ball 1, moving at speed 2m/s, strikes billiard ball 2 (initially at rest) head on, but slightly off center. After the collision, billiard ball 1 continues forward with a speed of 1m/s at an angle of 30 degrees, with respect to its initial direction?

a) What is the velocity (speed and direction) of billiard ball 2 after the collision?

b) Is this collision elastic? Support your answer.

c) Is the center of mass of the system moving? Support your answer.

d) If so, is it also accelarating? Support your answer.

Explanation / Answer

Here,

m1 = m2 = m
v1 = 2 m/s
v1'x = 1*cos30 = 0.866 m/s
vi'y = 1*sin30 = 0.5 m/s

A)
from conservation of momentum we have :

m1v1x = m1v1'x + m2v2'x

v1x = v1'x + v2'x
2 = 0.866 + v2'x

v2'x = 1.134 m/s

also in y direction :

m1v1y' = m1v2'y

v2'y = 0.5 m/s

Vnet = sqrt(v2x'^2 + v2'y^2)
Vnet = sqrt(1.134^2 + 0.5^2)
Vnet = 1.24 m/s

A = arcTan(vy/vx)
A = arcTan(0.5/1.134)
A = arcTan(0.44)
A = 23.79 degrees

B)
no the collision in no elasticas kinectic energy and momentum is not conserved

C)
centre of mass of system is moving as balls are moving

D)
as there is no external force on system therefore there will no acceleration.

Related Questions

Navigate

• Browse (All)
• Browse B
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.