A 30 kg. balloon is filled with 100 m to the third power of helium. how much force is needed to hold it down?

bouyancy force = weightairin100m^3-weightHein100m^3

force needed=bouyancy force-30kg*g

how do you get the weight? YOu need to make assumptions about pressure and temperature.

0.81 KN

To calculate the force needed to hold down the balloon, we need to consider the buoyant force acting on it and the downward force due to gravity.

1. Calculate the buoyant force:
The buoyant force is equal to the weight of the displaced air. Since the balloon is filled with helium, it displaces an equivalent volume of air.

The density of air at sea level is approximately 1.225 kilograms per cubic meter. So, the weight of the displaced air can be calculated as:
Weight of displaced air = Volume of air * Density of air
= 100 m^3 * 1.225 kg/m^3

2. Calculate the gravitational force acting on the balloon:
The gravitational force can be calculated using the formula:
Force = mass * acceleration due to gravity
= 30 kg * 9.8 m/s^2

3. Calculate the force needed to hold down the balloon:
The force needed to hold down the balloon is the difference between the buoyant force and the gravitational force:
Force needed = Weight of displaced air - Gravitational force

Now, let's calculate the force needed to hold down the balloon:
Weight of displaced air = 100 m^3 * 1.225 kg/m^3 = 122.5 kg
Gravitational force = 30 kg * 9.8 m/s^2 = 294 N
Force needed = 122.5 kg - 294 N

Therefore, the force needed to hold down the balloon is the difference between the weight of the displaced air and the gravitational force.

To calculate the force needed to hold down the balloon, we need to consider the buoyant force and the weight of the balloon. The buoyant force is the force exerted on an object immersed in a fluid (in this case, air) and is given by Archimedes' principle, which states that the buoyant force is equal to the weight of the fluid displaced by the object.

First, let's calculate the weight of the balloon, which is given by the formula:

Weight = mass × gravity

where:
- Weight is the force due to gravity acting on the object,
- mass is the mass of the balloon, and
- gravity is the acceleration due to gravity, which is approximately 9.8 m/s².

Weight = 30 kg × 9.8 m/s²

Weight = 294 N

Next, let's calculate the weight of the displaced air in the balloon. Since the balloon is filled with helium, which is less dense than air, it will displace an amount of air equal to the volume of the balloon. Given that the balloon is filled with 100 m³ of helium, the weight of the displaced air is:

Weight of displaced air = density of air × volume of air × gravity

The density of air is approximately 1.225 kg/m³.

Weight of displaced air = 1.225 kg/m³ × 100 m³ × 9.8 m/s²

Weight of displaced air ≈ 1,199 N

Finally, the force needed to hold the balloon down is the difference between the weight of the balloon and the weight of the displaced air:

Force needed = Weight - Weight of displaced air

Force needed = 294 N - 1,199 N

Force needed ≈ -905 N

The negative sign indicates that the force needed is in the upward direction, opposing the weight of the balloon. Therefore, to hold the balloon down, a force of approximately 905 N is required.