Author Question: A 4.0-kg mass, initially at rest on a horizontal frictionless surface, is struck by a 2.0-kg mass ... (Read 139 times)

humphriesbr@me.com · **on:** Jul 28, 2018

A 4.0-kg mass, initially at rest on a horizontal frictionless surface, is struck by a 2.0-kg mass moving along the x axis with a speed of 8.0 m/s. After the collision, the 2.0-kg mass has a speed of 4.0 m/s at an angle of 37 from the positive x axis. What is the speed of the 4.0-kg mass after the collision?
a. 2.0 m/s
b. 2.7 m/s
c. 4.9 m/s
d. 2.4 m/s
e. 3.6 m/s

Question 2

A 4.2-kg object, initially at rest, explodes into three objects of equal mass. Two of these are determined to have velocities of equal magnitudes (5.0 m/s) with directions that differ by 90. How much kinetic energy was released in the explosion?
a. 70 J
b. 53 J
c. 60 J
d. 64 J
e. 35 J