Lifting Force - Lab Report

1. Koya University
Faculty Of Engineering
Chemical Engineering Department – 2nd stage
Supervised by:
Mrs. Lameha and Mr. Daban
Prepared by:
Safeen Yaseen Jafar
Lab Report
Experiment Name
Lifting Force
Experiment Date
21/10/2020
Submit Date
23/10/2020

2. Table of Content
Subject Pages
Aim/Objective of Experiment………………......……………………………. 1
Theory/Introduction...…….........…………………………………………….. 2
Methology of Tools...………......…………………………………………… 3
Procedure…..…………………......…………………………………………. 4
Table of Reading.…………………...……………………………………….. 5
Sample of Calculation.....…………...……………………………………….. 6-7
Table of Calculation………………...……………………………………….. 8
Discussion………………………....………………………………………… 9

3. 1
Aim/Objective of This Experiment
Finding the lifting force on an immersion body in a liquid (water – H2O).

4. 2
Theory/Introduction
When a body is immersed in a liquid, a lifting force F, acts upon it which corresponds to the
force due to weight of the displaced liquid:
FA = ρ × g × V … … … … … 𝒆𝒒(𝟏)
V: Volume of immersed body OR Volume of displaced water
ρ: Density of liquid.
The lifting force FA is always directed upwards, and thus brings about an apparent weight
loss of the immersed body:
𝐅𝐆 in H2O = 𝐅𝐆 in air − 𝐅𝐀 … … … … … 𝒆𝒒(𝟐)

5. 3
Methology of Tools
4
5
1. Overflow vessel.
2. Sample.
3. Beaker.
4. Balancer.
5. Stand.

6. 4
Procedure of The Experiment
1. Fill the overflow vessel 1 with water until the liquid level h is precisely below the
outlet pipe.
2. Position the empty measuring cup 3 underneath the outlet pipe.
3. Weigh out the three bodies 2 made of aluminum, brass and 1- polyoxymethylene POM
using the spring balance: Force due to weight FG for each body.
4. Completely immerse the body suspended on the spring balance in h the overflow
vessel: Read off the displayed weight FG, Water Read off the overflowed water
volume V.

7. 5
Table of Reading
No.
Materials of the
body
FG in air (N) FG in water (N)
Volume
Displaced (ml
or cm3
)(Vdis)
1 Aluminum (Al) 2.26 1.55 90
2 Brass (Cu) 4.65 4.1 60.1
3
Polyoxymethylene
(POM)
1.25 0.7 55

8. 6
Sample of Calculation
1. For Aluminum
ρ of H2O = 1000 kg/m3
, g = 9.81 N/kg , V = 90 ml = 90 cm3
FA = ρ × g × V
FA = 1000 kg/m3
× 9.81 N/kg × 90 cm3
×
1 𝑚3
1 × 106 𝑐𝑚3
FA = 0.8829 N
FG H2O, th. = FG in air - FA
FG H2O, th. = 2.26 N - 0.8829 N
FG H2O, th. = 1.37 N
2. For Brass
ρ of H2O = 1000 kg/m3
, g = 9.81 N/kg , V = 60.1 ml = 60.1 cm3
FA = ρ × g × V
FA = 1000 kg/m3
× 9.81 N/kg × 60.1 cm3
×
1 𝑚3
1 × 106 𝑐𝑚3
FA = 0.5895 N
FG H2O, th. = FG in air - FA
FG H2O, th. = 4.65 N - 0.5895 N
FG H2O, th. = 4.06 N

9. 7
3. For Polyoxymethylene
ρ of H2O = 1000 kg/m3
, g = 9.81 N/kg , V = 55 ml = 55 cm3
FA = ρ × g × V
FA = 1000 kg/m3
× 9.81 N/kg × 55 cm3
×
1 𝑚3
1 × 106 𝑐𝑚3
FA = 0.5395 N
FG H2O, th. = FG in air - FA
FG H2O, th. = 1.25 N - 0.8829 N
FG H2O, th. = 0.7105 N

10. 8
Table of Calculation
No.
Materials of the
body
FG (N)
FG in water
(N)
FA (N)
FG water, th.
(N)
1 Aluminum (Al) 2.26 1.55 0.8829 1.37
2 Brass (Cu) 4.65 4.1 0.5895 4.06
3
Polyoxymethylene
(POM)
1.25 0.7 0.5395 0.7105

11. 9
Discussion
1. Discuss the difference between the values of the calculating and readings.
Table of reading show us the values that we read or record in our practical activity in
laboratory. But Table of calculation show us the theoretical values which taken from these
equations:
FA = ρ × g × V .......................eq(1)
FG H2O, th. = FG in air - FA .........................eq(2)
2. Why is the weight of the body in the air greater than the weight of it in the water?
Because of the lifting force in water push the material away from inside liquid (water) to
outside of the liquid (water).
3. What is happening if the weight of the body in the water (FG, water) becomes zero.
It is mean that the force on the body of the material is equal to the force that push away from
the inside of the water (FG in air = FA).
4. the Vdis for brace in greater than Vdis for Aluminum and Polyoxymethylene, why ?
The brace has the biggest value of FG in water So that occur the biggest of volume of water
overflow from the overflow vessel to beaker.
5. Why the boat float on water while the iron nail sinks?
Because of the type of body of the material. also their density of both of boat and iron are
different from each other. Water’s density is more than the overall density of boat, and iron
has the less density than water. Due to this the iron nail sinks while the boat floats on the
surface of the water.