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A small block of mass m is fixed at upper end of a massless vertical spring of spring constant K = 4mg/L and natural length '10L'. The lower end of spring is free and is at a height L from fixed horizontal floor. The spring is initially unstressed and the spring-block system is released from rest.
When free end of spring just touches the ground, the velocity of the block at that instant is 'v'. Then which of the following is (are) true :
(a) The magnitude of velocity 'v' is \(\sqrt {2gL}\).
(b) Block wil regain the velocity of magnitude 'v', when compression in spring is \(\frac {L}{2}\).
(c) Block will reach the velocity of magnitude 'v', twice in a cycle.
(d) Block will reach the velocity of magnitude 'v', four times in a cycle.
Updated Tue, 11 Dec 2018 03:39 pm
Sir plz explain 1st and 2nd questions
Q1
An ideal gas heat engine operates in a Carnot cycle between 227 ºC and 127 ºC. It absorbs 6 kcal at the higher temperature. The amount of heat (in Kcal) converted into work is equal to
(a) 1.6
(b) 1.2
(c) 4.8
(d) 3.5
Q2
One mole of an ideal gas at an initial temperatue of TK does 6 R joules of work adiabatically. If the ratio of specific heats of this gas at constant pressure and at constant volume is 5/3, the final temperature of gas will be
(a) (T + 2.4) K
(b) (T - 2.4) K
(c) (T + 4) K
(d) (T - 4) K
Updated Tue, 11 Dec 2018 12:24 pm
