HELP PL 1) One single water wave travels its own length in 0.8 seconds along the side of a pier. There are 15 waves along the 60 m pier. How fast are the waves travelling in m/s?
2)Radio waves are used in GPS systems to locate people. A signal sent from a satellite reaches a receiver on Earth in 0.12 seconds. How far away is the satellite in km?
3) A bolt of lightning strikes 4 km away. How long does it take for the sound waves from the thunder to reach you?

Agas expands from an initial volume of 0.040 m^3 and an initial pressure of 210 kpa to a final volume of 0.065 m^3 while its temperature is kept constant. how much work is done by the system?

If the work required to stretch a spring 3 ft beyond its natural length is 15 ft-lb, how much work is needed to stretch it 27 in. beyond its natural length?

The temperature in gavin's oven is a sinusoidal function of time. gavin sets his oven so that it has a maximum temperature of 280°f and a minimum temperature of 240°. once the temperature hits 280°, it takes 20 minutes before it is 280° again. gavin's cake needs to be in the oven for 30 minutes at temperatures at or above 270°. he puts the cake into the oven when it is at 260° and rising. how long will gavin need to leave the cake in the oven? (round your answer to the nearest minute.)