A large blue marble of mass 3.5 g is moving to the right with a velocity of 15 cm/s. The large marble hits a small red marble of mass 1.2 g that is moving to the right with a velocity of 3.5 cm/s. After the collision, the blue marble moves to the right with a velocity of 5.5 cm/s.

What is the magnitude of the final velocity of the red marble?

9.2 cm/s

14 cm/s

24 cm/s

31 cm/s

Question

Bucky

Physics

5 March, 23:57

A large blue marble of mass 3.5 g is moving to the right with a velocity of 15 cm/s. The large marble hits a small red marble of mass 1.2 g that is moving to the right with a velocity of 3.5 cm/s. After the collision, the blue marble moves to the right with a velocity of 5.5 cm/s.

What is the magnitude of the final velocity of the red marble?

9.2 cm/s

14 cm/s

24 cm/s

31 cm/s

+5

Answers (1)

Know the Answer?

Lilian Mclean · Answer 1

According to the elastic conservation momentum

m1v1 + m2v2 = m1V1 + m2V2

v: velocity before collision, V after collision

the magnitude of the final velocity of the red marble

m1v1 + m2v2 = m1V1 + m2V2

V2 is the final velocity we must find

V2 = 1 / m2 (m1v1 + m2v2 - m1V1)

= 1/1.2 (3.5x15 + 1.2x 3.5 - 3.5x 5.5) = 63.29 cm/s