Question

a 3.00 kg lump of clay is moving to the right at a speed of 10.0 m/s. a 1.00 kg rock, which is moving to the left with a speed of 6.00 m/s, collides with and sticks to the clay. after they collide they move off together. find the following: a. find the magnitude and direction of the velocity of the masses after the collision. b. find the total kinetic energy of the system of masses before the collision, c. find total kinetic energy of the system of masses after the collision, d. find the change in kinetic energy of the system of masses during the collision

Answer 1

a. 6.0 m/s to the right

b. 168 J

c. 72 J

d. 96 J

Step-by-step explanation:

a.

(3.0 kg)(10 m/s) + (1.0 kg)(-6.0 m/s) = (3.0 + 1.0 kg)v

24 kg·m/s = (4.0 kg)v

v = (24 kg·m/s)/(4.0 kg) = 6.0 m/s to the right

b.

KEbefore = 1/2(3.0 kg)(10.0 m/s)² + 1/2(1.0 kg)(-6 m/s)² = 150 J + 18 J = 168 J

c.

KEafter = 1/2(4 kg)(6.0 m/s)² = 72 J

d.

ΔKE = 168 J - 72 J = 96 J

96 J of KE converted to thermal energy as a result of the collision