Question

~~~~NEED HELP ASAP~~~~

Block A slides into block B along a frictionless surface. They are moving in the direction from left o the right.

Block A= 3kg

Block B= 4kg

Block A velocity before collision =30m/s.

Block B velocity before collision = 15 m/s

The velocity of block B after the collision is 20m/s.


a.) What is the velocity of block A after collision?

b.) Is the collision elastic? Show work to explain answer why or why not.

Answer 1

Answer:

Block A velocity is 23.33 m/s and the collission is not elastic.

Explanation:

a) m1v1 + m2v2 = m1v1' + m2v2'

Plug in givens

90+60=3v1'+80

solve for v1'= 23.33m/s

b) Find the initial and final kinetic energy of Block B

Ki= 1/2(4)(15)^2 + 1/2(3)(30)^2 = 1800 J

Kf= 1/2(4)(20)^2 + 1/2(3)*(23.33)^2= 1616.433J

Since Ki does not equal Kf the collision is not elastic