Based on the principles of convection, conduction and thermal radiation, which scenario below is most similar to the following situation?

You put a heating pad on your back after exercising.
A) Feeling a metal wire get warmer as you roast a marshmallow over a fire.
B) Warm air rising in a room where the air is moving.
C) The sun warming up the roof on a house.
D) Cold water sinking in a pot of water being warmed up

A250-n box is at rest on a frictionless horizotal floor. then a person shoves the box with a non-zero force of magnitude p. which statement best describes the relationship betweeen p and the motion of the box after it was shoved? -the box will not move when p< 250n but otherwise will accelerate at a constant rate that is directly proportional to p - the box will begin moving at a speed that is directly proportional to p, then will gradually slow to a halt -the box will move with constant velocity at a speed that is directly proportional to p -box will accelerate across the floor at a constant rate that is directly proportional to p

Which of the following are guidelines to follow for obtaining accurate observations

Refrigerant-134a flows through a carnot heat pump cycle at 0.5 kg/s. it is known that the maximum absolute temperature in the cycle is 1.1 times the minimum absolute temperature, and the net power input to the cycle is 2.5 kw. if the refrigerant changes from a saturated vapor to a saturated liquid during the heat rejection process, determine the maximum magnitude of the enthalpy of vaporization for this process in kj/kg (with 3 significant figures).