A 45-kg boy pulls a wagon with a force of 38 N for a distance of 550 m. If the boy takes 240 s, what is the power expended by the boy? (Round your answer to two significant figures.)

An object with initial temperature 130 ∘ f is submerged in large tank of water whose temperature is 50 ∘ f . find a formula for f ( t ) , the temperature of the object after t minutes, if the cooling constant is k = − 0.2 . remember newton's law of cooling (the rate of change of temperature with respect to time is equal to k times the difference between the temperature of the object and the surrounding temperature) ! : )