(a) During an ice skating performance, an initially motionless 80.0-kg clown throws a fake barbell away. The clown’s ice skates allow her to recoil frictionlessly. If the clown recoils with a velocity of 0.500 m/s and the barbell is thrown with a velocity of 10.0 m/s, what is the mass of the barbell? (b) How much kinetic energy is gained by this maneuver? (c) Where does the kinetic energy come from?

Step-by-step solution In this problem a ice skating act was perform by a clown who throws a fake barbell away ,so as per the given data we have to find out the mass of the barbell , gain in the kinetic energy and the point from which the kinetic energy is generated. Step 1 of 8 (a) For a collision, the momentum will be conserved. So, …… (1) Here is the mass of skates, is the mass of barbell, is the velocity of skates, is the velocity of barbell and is the velocity after collision. Step 2 of 8 Substitute in equation (1) and get: Hence, mass of barbell is . Step 3 of 8 (b) The expression of initial kinetic energy is: …… (2) Here is the mass of skates, is the mass of barbell, is the velocity of skates and is the velocity of barbell. Step 4 of 8 Substitute in the equation (2) and get: Hence, the initial kinetic energy is 2.2 × 10 J.