A spherical weather balloon is filled with hydrogen until its radius is 3.00 m.

Question

A spherical weather balloon is filled with hydrogen until its radius is 3.00 m. Its total mass including the instruments it carries is 10.0 kg.

(a) Find the buoyant force acting on the balloon, assuming the density of air is 1.29 kg/m3.
N

(b) What is the net force acting on the balloon and its instruments after the balloon is released from the ground?
N

(c) Why does the radius of the balloon tend to increase as it rises to higher altitude?
Because the external pressure (increases/decreases) with (decreasing/increasing) altitude.

Explanation / Answer

buoyant force = Vg = (4/3)r3g = 1577.57 N

Net force = buoyant force - weight = 1577.57 - 10*9.8 = 1479.57

The ballon rises to the altitude because external pressure decreases with altitude. As we move up air becomes less dense and hence pressure of air over ballon decreases and the ballon stops moving up when a limit is reached.

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.