60 649
Assignments Done
97,8%
Successfully Done
In April 2018

Answer to Question #12287 in Mechanics | Relativity for jim murillo

Question #12287
an 11.7 kg object is at rest on a perfectly frictionless surface when it is struck head on by a 3.9 kg object moving at 18 m/s. if the collision is perfectly elastic, what is the speed of the 11.7 kg object?
Expert's answer
Let's use the momentum conservation law:

m1·u1 + m2·u2 = m1·v1 + m2·v2.& (1)

Here m1 is the mass of the first object (11.7 kg), m2 is the mass of the second object (3.9 kg), u1 and u2 are initial velocities of the first and the second objects respectfully and v1 and v2 are their velocities after collision.

The equation expressing conservation of kinetic energy is

m1·u1² + m2·u2² = m1·v1² + m2·v2².& (2)

Using expressions (1) and (2) we'll get

v1 = (m1-m2)·u1/(m1+m2) + 2·m2·u2/(m1+m2),

or, substituting given masses and initial velocities

v1 = (11.7-3.9)·0/(11.7+3.9) + 2·3.9·18/(11.7+3.9) = 9 m/s.

So, 11.7 kg object obtain speed 9 m/s.

Need a fast expert's response?

Submit order

and get a quick answer at the best price

for any assignment or question with DETAILED EXPLANATIONS!

Comments

No comments. Be first!

Leave a comment

Ask Your question

Submit
Privacy policy Terms and Conditions