16 Work Energy and Power 11 A spring is executing motion about equilibrium position x 0 where we take potential energy of spring to be zero The spring is oscillating between x and x position with a mass m attached During motion maximum speed of spring will be INCERT P 124 1 2 2 3 x 12 The graph between potential energy U of a spring versus its position x is best shown by graph equilibrium x 0 INCERT Pg 124 Ut 0 E U 0 x 13 Consider a situation in which a car of mass 2000 kg moving with speed of 54 km h on a smooth road and colliding with a horizontal mounted spring of spring constant 12 5 10 Nm What is maximum compression of INCERT Pg 124 2 6 m spring 1 4 m 3 8 m 4 1 m 14 An elevator can carry a maximum load of 900 kg elevator passengers is moving up with constant speed of 2 m s A constant frictional force of 5000 N opposes the INCERT Pg motion What minimum power is delivered by motor in HP 1 37 5 HP 3 42 5 HP 4 50 2 HP 15 Two objects with mass m 2 kg and m 3 kg collides perfect inelastically The particles were moving with speed of 10 ms and zero NCERT Pg 131 respectively before collision The loss of KE on collision is 1 60 J 2 40 J 3 100 J 4 90 J 16 Consider a collision between two identic billiard balls with equal masses m m First ball was at rest and second hits it edge Second ball after hitting mo ind Regd Office Aakash Tower 8 Pusa Re 17