A heat engine uses a heat source at 730°C and has an ideal (Carnot) efficiency of 26%. To increase the ideal efficiency to 41%, what must be the temperature (in °C) of the heat source?

Ablock having mass m slides down an inclined plane. the force of friction between the block and the inclined plane is f, the block's weight is m g, and the normal force is n. (a) draw a free – body force diagram showing the forces acting on the block. (b) write down all relevant newton’s equations for a given situation.