A girl has a body weight of 400n. What upthrust does she need to float?
The girl is 400N .And she floats so the upthrust and the gravity is balanced were,the opposite force is also equal.
So,400 is the Upthrust force
Duh...400N.
Well, if she wants to float, she'll need an upthrust greater than her body weight. But hey, let's not take this too seriously! Maybe she can start by asking some ducks for assistance, since they're quite experienced in floating. Then again, she could always try inflating a bunch of balloons and tying them to her arms. Just imagine her floating through the air like a giant human balloon! That would definitely make for an interesting sight, wouldn't it?
To calculate the upthrust required for an object to float, we need to know the density of the fluid it is floating in.
The upthrust (also known as buoyant force) is equal to the weight of the fluid displaced by the object. According to Archimedes' principle, an object will float if the upthrust is equal to or greater than its weight.
Let's assume that the girl wants to float in water, which has a density of 1000 kg/m^3.
Step 1: Convert the girl's body weight to Newtons.
The weight of the girl is given as 400 N, so no conversion is required.
Step 2: Convert the weight to mass.
Using the formula: weight = mass × gravity, where gravity ≈ 9.8 m/s^2.
mass = weight / gravity
mass = 400 N / 9.8 m/s² ≈ 40.82 kg
Step 3: Calculate the volume of water displaced.
The volume of water displaced can be calculated using the formula:
volume = mass / density
volume = 40.82 kg / 1000 kg/m^3 ≈ 0.04082 m^3
Step 4: Calculate the upthrust required.
The upthrust (buoyant force) is equal to the weight of the fluid displaced, so:
upthrust = weight of fluid displaced
upthrust = volume × density × gravity
upthrust = 0.04082 m^3 × 1000 kg/m^3 × 9.8 m/s² ≈ 399.9996 N
Therefore, the girl needs an upthrust of approximately 400 N to float in water.
To calculate the upthrust required for an object, such as a girl, to float, we need to consider the principles of buoyancy. Buoyancy is the upward force exerted by a fluid (in this case, the liquid in which the girl would be floating) on an object immersed in it. It counteracts the force of gravity and allows objects to float.
The upthrust or buoyant force is equal to the weight of the fluid displaced by the object. In this case, assuming the girl would be floating in water, the upthrust needed can be calculated using Archimedes' principle.
Step 1: Determine the density of water:
The density of water is approximately 1000 kg/m³.
Step 2: Convert the girl's weight from Newtons to kilograms:
To convert from Newtons (N) to kilograms (kg), divide the given weight by the acceleration due to gravity (approximately 9.8 m/s²).
Weight in kg = Weight in N / 9.8
Step 3: Calculate the volume of water displaced:
Using Archimedes' principle, the volume of water displaced is equal to the volume of the submerged part of the girl's body. We assume her body has the same density as water, so the volume of water displaced is equal to her body volume.
Step 4: Calculate the upthrust/buoyant force:
Upthrust (in Newtons) = Volume of water displaced x Density of water x Acceleration due to gravity
By following these steps and plugging in the appropriate values, you can determine the upthrust required for the girl to float.