1. The speed of sound in water is approximately 1500 m/s. a) What is the frequency of a sound wave with a wavelength of 1.5m. b) What is the period of this wave. 2. Water waves enter a dock at a rate of 120 crests per minute. At the dock are two poles 12m apart. A worker watches a particular wave crest pass from one pole to another in 4sec. a) Calculate the frequency of wave motion; b) Wavelength of the waves.

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) ! : )