7 V 0.5kg
in Practice
1. A mass spring system is in SHM in the horizontal direction. If the mass is 0.25
kg, spring constant is 12N/m, and the amplitude is 15 cm,
a) what is the maximum speed of the mass?
Ans: 1.01 M/S
b) What is the speed at a half-amplitude position? Ans: 0.12 M/S
2. The mass m is now stretched a distance of 8 cm and held. What is the potential ener-
gy? (k = 196 N/m)
Ans: 0.6272)

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) ! : )