A spring scale is used to measure the weight of travel bags at the airport. A weight of15 N causes its spring to extend by 3 cmFormula 1( Force F = Elastic constant k X Extension x)Formula 2( Weight W = Mass m X gravity g),where value of g = 10 m/s2

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) ! : )