[2] (c) A helium-filled weather balloon is held at ground level. The volume of the balloon is 4800 mº.
The pressure of the helium is 98 kPa.
The balloon is released and rises to a height where the volume of the balloon is 7200 m
(i)
Calculate the new pressure of the helium. Assume that the temperature stays constant.
pressure =
[2]

Afisherman notices that his boat is moving up and down periodically without any horizontal motion, owing to waves on the surface of the water. it takes a time of 2.20 s for the boat to travel from its highest point to its lowest, a total distance of 0.670 m . the fisherman sees that the wave crests are spaced a horizontal distance of 5.80 m apart. (a) how much is the wavelength? (b) find the period of the wave. (c) how fast are the waves traveling? (d) what is the amplitude a of each wave?