A person can lift 45 kg ( aprox 100lb). Using specific gravity as 10.17
How many cubic meters of the metal could the person lift in
a) air ?
b) water ?
c) in water ?
Thanks
(a) Get the Volume by using V = Weight/(Density)= M g/(10.17*10^3 kg/m^3)
Ignore the buoyancy effect of air; it is negligible.
You get V = 0.043 m^3
(b) and (c) look the same to me. The effective density in water (with buoyancy force subtracted) is 9.17*10^3 kg/m^3. Repeat (a) with that instead of 10.17*10^3 in the denominator
Oh..
is actually
C)to find how many actual kg of metal is in this in air and in water?
mass of metal in water: .110kg
mass of metal in air: .122kg
mass of displaced water: .00706kg
Thanks
Since they tell you in the beginning that 45 kg can be lifted, I don't understand how you come up with 122 kg, or 0.122 kg, as the "mass of metal in air" that is "in this".
You must be omitting something
Oh..I didn't omit anything, I just added in the info of my recorded info from my lab...I wasn't sure if I'd need that.
I guess not then.
This question was a extra calculation question after the lab was done but I wasn't sure how to do this.
so the question and just the question with nothing extra added:
C)to find how many actual kg of metal is in this in air and in water?
sorry for the confusion =)
To calculate the volume of the metal that can be lifted in each scenario, we need to use the equation:
Volume = Mass / Density
The density of a substance is determined by its specific gravity, which is the ratio of the density of the substance to the density of water. In this case, the specific gravity is given as 10.17, which means the metal is 10.17 times denser than water.
a) To calculate the volume of the metal that can be lifted in air, we assume that the density of air is negligible. Therefore, the volume of metal can be calculated using the mass of the metal (45 kg) divided by the density of air (which is very close to 0):
Volume in air = Mass / Density of air
= 45 kg / 0
= Infinity
Therefore, in air, there is no limit to the volume of metal that can be lifted.
b) To calculate the volume of the metal that can be lifted in water, we need to use the specific gravity to determine the density of the metal:
Density of metal = Specific gravity x Density of water
= 10.17 x 1000 kg/m^3 (since the density of water is about 1000 kg/m^3)
= 10,170 kg/m^3
Now we can calculate the volume of the metal in water:
Volume in water = Mass / Density of water
= 45 kg / 10,170 kg/m^3
= 0.0044 m^3
= 4.4 liters
Therefore, a person can lift approximately 4.4 liters of the metal in water.
c) Finally, to calculate the volume of the metal that can be lifted underwater, we need to consider the buoyancy force acting on the metal. When an object is submerged in a fluid, it experiences an upward force equal to the weight of the fluid displaced.
Since the metal is denser than water (specific gravity of 10.17), it will displace less water than its own weight. Therefore, the effective weight of the metal underwater will be reduced.
To calculate the volume of the metal in water, we can use Archimedes' principle:
Buoyant force = Weight of water displaced
= Density of water x Volume submerged x Gravity
Weight of the metal = Mass x Gravity
Buoyant force = Weight of the metal underwater
Density of water x Volume submerged x Gravity = Mass x Gravity
Density of water x Volume submerged = Mass
Volume submerged = Mass / Density of water
= 45 kg / 1000 kg/m^3 (density of water)
= 0.045 m^3
= 45 liters
Therefore, a person can lift approximately 45 liters of the metal in water while being submerged underwater.