Buoyant forces on hot-air balloon

[franklyn]

hey guys i have an exam tomorrow so i guess a uick reply would help .. my mind is totally blocked as to how to solve this question.

hot air balloon experiences an acceleration of 1.10m/s total mass equals 315kg
a) what is the upward (buoyant) force on the system
b) the baloonist wishes to change the acceleration to zero there is no fuel ...determine the mass of ballast that must be thrown of ...air resistance neglegible..

if anyone could answer this it would really help.

 

[Gokul43201]

Sorry franklyn, but we can't help you (read the rules) unless you make an effort.

Calm down. Do not panic.

What ideas do you have ? What concepts/equations might be involved here ?

 

[wais]

Hi there,

I understand that you have an exam tomorrow and are feeling overwhelmed. I will try my best to help you with this question about buoyant forces on a hot air balloon.

First, let's define the buoyant force. It is the upward force exerted on an object by a fluid (in this case, air) that opposes the weight of the object. In this problem, the hot air balloon is experiencing an acceleration of 1.10m/s and has a total mass of 315kg.

a) To find the upward (buoyant) force on the system, we can use the formula Fb = ρVg, where ρ is the density of air, V is the volume of the balloon, and g is the acceleration due to gravity (9.8m/s^2). Since the acceleration is given in the problem, we can use the formula Fb = m(g + a), where m is the mass of the balloon. Plugging in the values, we get Fb = (315kg)(9.8m/s^2 + 1.10m/s) = 3256.5N. So, the upward force on the system is 3256.5N.

b) Now, let's determine the mass of ballast that must be thrown off to change the acceleration to zero. Since the acceleration is caused by the weight of the balloon, we need to decrease the weight by throwing off some mass. Using the formula F = ma, we can find the mass that needs to be thrown off. Rearranging the formula, we get m = F/a. Plugging in the values, we get m = 3256.5N/1.10m/s^2 = 2960.45kg. So, the mass of ballast that needs to be thrown off is 2960.45kg.

I hope this helps you with your exam preparation. Good luck on your exam!