buoyancy conceptual question - physics mcat

Started by MC789
This forum made possible through the generous support of SDN members, donors, and sponsors. Thank you.
Get help with your application

Use all the free resources available to you from SDN: articles, guides, expert advising, forums discussions, and school research.

MC789

Full Member
7+ Year Member
Advertisement - Members don't see this ad
hey guys,

I'm confused on the answer to this question:
Q: as a hot air balloon ascends upward at a constant speed, a package is dropped out of the balloon. at the instant the package is released, the momentum of the balloon:

correct answer: momentum of balloon increases
my answer: the momentum of balloon decreases

in the past I noticed I intend to ignore the given equations in the passage to answer the questions and thats the safest way to go. so I used the buoyancy equation B = density of fluid times volume of fluid times gravity.

I chose momentum decreases because when mass is thrown out, the mass of the balloon (mass = density times volume) decreases and gravity is constant. so B = m times g, and m decreases and g is constant so B should decrease. when bouyant force decreases, there isn't much of a push on the balloon so its momentum decreases.

could someone explain why I am wrong?
 
hey guys,

I'm confused on the answer to this question:
Q: as a hot air balloon ascends upward at a constant speed, a package is dropped out of the balloon. at the instant the package is released, the momentum of the balloon:

correct answer: momentum of balloon increases
my answer: the momentum of balloon decreases

in the past I noticed I intend to ignore the given equations in the passage to answer the questions and thats the safest way to go. so I used the buoyancy equation B = density of fluid times volume of fluid times gravity.

I chose momentum decreases because when mass is thrown out, the mass of the balloon (mass = density times volume) decreases and gravity is constant. so B = m times g, and m decreases and g is constant so B should decrease. when bouyant force decreases, there isn't much of a push on the balloon so its momentum decreases.

could someone explain why I am wrong?
Hot Air Balloon & Momentum

Hopefully that link works. There you go.