Two identical ball bearings in contact with each other and resting on a frictionless table is hit head-on by another ball bearing of the same mass moving initially with a speed V. If the collision is elastic, which of the following figure is a possible result after collision?
Let m be the mass of each ball Total KE of the system before collision =21mv2 Total KE of the system after collision is Case (i) E1=21(2m)(2v)2=41mv2 Case (ii) E2=21mv2 Case (iii) E3=21(3m)(2v)3=61mv2 ∴ case (ii) is only possible since KE of the system is conserved
