A steam engine intakes 50 g of steam at 100$$^\circ$$C per minute and cools it down to 20$$^\circ$$C. If latent heat of vaporization of steam is 540 cal g^$$-$$1, then the heat rejected by the steam engine per minute is __________ $$\times$$ 10³ cal.

(Given : specific heat capacity of water : 1 cal g^$$-$$1 $$^\circ$$C^$$-$$1)

A monoatomic gas performs a work of $${Q \over {4}}$$ where Q is the heat supplied to it. The molar heat capacity of the gas will be ______________ R during this transformation. Where R is the gas constant.

0.056 kg of Nitrogen is enclosed in a vessel at a temperature of 127$$^\circ$$C. Th amount of heat required to double the speed of its molecules is ____________ k cal.

Take R = 2 cal mole^$$-$$1 K^$$-$$1)