The formula for frequency is f = 1/T where f is frequency and T is period in seconds.
You have you period which is 0.008s and that is all you will need to solve or frequency in a wave:
f = 1/2
f = 1/0.008s
f = 125Hz
5.6 g/ml. That is the density.
1.7 Btu
1 watt = 3.41214 Btu/h
1watt * 1h = 3.41214 Btu/h * h
1 = 3.41214 Btu/ (watt*h)/
0.5 watt * h = 0.5 watt*h * 3.41214 Btu/(watt*h) = 1.706 Btu