posted by Mikey on .
a hot air balloon rise above the ground, accelerating upwards at a rate of 2 m/s^2. The total mass of the hot air balloon and it occupants is 400kg. the density of the air is 1.3 kg/m^3.
a) Determine the volume if the hot air balloon.
b) if this acceleration is maintained for 5 seconds, how high will the balloon rise?
a) The probably want you to use
Force = Mass* aaceleration
to get the net force on the balloon, and then use
Net Force = Buoyancy - Weight
to get the buoyancy force. Once you have that, you can get the volume of the balloon using Archimedes Principle.
This approach neglects the atmospheric drag force, which might be appreciable, but perhaps not for the first 5 seconds.
b) Distance risen = (1/2) a t^2
(if a remains constant)