The function x = (3.0 m) cos[(5ï€ rad/s)t + ï€/2 rad] gives the simple harmonic motion of a body. find the following values at t = 3.0 s.
(a) the displacement m
(b) the velocity (include the sign of the value in your answer.) m/s
(c) the acceleration (include the sign of the value in your answer.) /s^2
(d) the phase of the motion
(e) the frequency of the motion
(f) the period of the motion

An ice-making machine inside a refrigerator operates in a carnot cycle. it takes heat from liquid water at 0.0 degrees celsius and rejects heat to a room at a temperature of 19.2 degrees celsius. suppose that liquid water with a mass of 76.3kg at 0.0 degrees celsius is converted to ice at the same temperature. take the heat of fusion for water to be l_f = 3.34*10^5 j/kg. how much energy e must be supplied to the device? express your answer in joules.