In an experiment Rahul burnt 4 kg fuel and the heat produced was measured to be 160,000 kJ and Raj burnt 2 kg of fuel and heat produced was measured to be 100,000kJ. Calculate the net calorific value of the fuels.

Ablock of mass m = 2.5 kg is attached to a spring with spring constant k = 790 n/m. it is initially at rest on an inclined plane that is at an angle of 28 degrees with respect to the horizontal, and the coefficient of kinetic friction between the block and the plane is k = 0.14. in the initial position, where the spring is compressed by a distance of a = 0.18 m, the mass is at its lowest position and the spring is compressed the maximum amount. take the initial gravitational energy of the block as zero. b) if the spring pushes the block up the incline, what distance, l, in meters will the block travel before coming to rest? the spring remains attached to both the block and the fixed wall throughout its motion.

Wavelength,frequency,and energy are related.what happens to a wave as it’s wavelength gets shorter?

How much energy must a refrigerator absorb from 225 g of water so that the temperature of the water will drop from 35°c to 5°c