A "massless" balloon is filled with 1.5 m^3 of helium. Gravity = 9.8 m/s^2. What is the maximum weight that it can lift in air? Assume density of air is 1.2 kg/m^3 ans that of helium is 0.177 kg/m^3. Answer in N.
2006-12-01 14:18:11 · 3 answers · asked by Jonathan V 1 in Science & Mathematics ➔ Physics
show me how to work it please
2006-12-01 14:24:13 · update #1
The mass of 1.5 m^3 of air is 1,5* 1.2 = 1.8 kg
The weight comes out to 1.8 kg * 9.8 m/s^2= 17.6 n
The mass of 1.5 m^3 of helium is 1.2*.177 = .2124 kg
The weight is .2124kg*9.8 m/s^2= 1.22 n
According to the Archimedes principle, the upward thrust of buoyancy is caused by the difference in weight of the two items.
17.6-1.22= 16.4 newtons
2006-12-01 14:35:13 · answer #1 · answered by eric l 6 · 0⤊ 0⤋
Weight of any object is volume x density x acceleration due to gravity.
Up thrust is the weight of air displaced = 1.5 x 1.2 x 9.8 N
Down force of helium balloon = 1.5 x 0.177 x 9.8.
Net upward force = 1.5 x (1.2 x 0.177) x 9.8. Volume x difference in densities x g.
Answer is 15 N.
2006-12-01 17:21:25 · answer #2 · answered by Pearlsawme 7 · 0⤊ 0⤋
see: http://en.wikipedia.org/wiki/Buoyant_force
2006-12-01 14:22:37 · answer #3 · answered by arbiter007 6 · 0⤊ 0⤋