A 1.0 kg lump of clay is sliding to the right on a frictionless surface with speed 2 m/s. It collides head-on and sticks to a 0.5 kg metal sphere that is sliding to the left with speed 4 m/s. What is the kinetic energy of the combined objects after the collision?

0J

Explanation:

Mass of the lump M1 = 1.0 kg, initial velocity of the lump U1 = 2m/s to the right,

mass of the metal sphere M2 = 0.5kg, initial velocity of the metal sphere M2 = - 4m/s to the left. using conservation law of momentum;

M1U1 + M2U2 = V (M1 + M2)

(1.0 * 2) + (0.5 * - 4) = V (1 + 0.5)

2 - 2 = V (1.5)

0 = V (1.5)

divide both side by 1.5

0/1.5 = V 1.5/1.5

V = 0

since final velocity after sticking together of the two masses equals zero then their combined kinetic energy will also equal to zero

1/2 V (M1 + M2)

1/2 * 0 * 1.5 = 0J