Physics experiment 1 Aiub

1. American International University-Bangladesh(AIUB)
Faculty of Science and Technology
DEPARTMENT OF PHYSICS
PHYSICS LAB 1
Group:1 Section:C3
Lab report on Verification of Newton’s second
Law by Atwood machine
Supervised by:
Dr Muhammad Habib Ullah

2. Theory
 Newtons second law of motion tells that force causes
acceleration and the relationship between net force acting on
an object, Fnet and its acceleration, a is Fnet=ma, where (m) is
the mass of the object.
 In Atwood Machine , two masses m and M are suspended by
a piece of inelastic light string that passes over a pulley in a
vertical plane as shown in the figure below.The two masses
are connected with a string because of this they must have
same tension,T and acceleration, a.

 M1=less mass
 M2=more mass

4. Apparatus
1)Pulley
2)Two weight hangers
3)Meter scale
4)String
5)Stop watch
6)Stamp and lamp

5. Procedure
 The lighter mass(m1) was held on the floor while attached to an
end of the string. At height (D) from the floor, the heavier mass
(m2)was attached to the end of the string. The height (D) was
measured with a measuring scale.
 The string was run over the pulley in the vertical plain . The
whole system was then released. The time for the heavier mass to
fall onto the floor was measured.
 The experiment was ran for 7 different mass differences (M-m).It
was made sure that (m+M)=700g was constant.
 Excel was used to plot graph of the experimental data( a exp vs
M-m).Slope was set (g/(M-m)) and was solved for M+m.

6. Experimental Data

7. Graph of acceleration and mass
differences

8. Analysis and Calculation

9. Results
 The experimental results from the Atwood
machine strongly support Newton’s 2nd
law of
motion. The observed relationship between
force and acceleration was consistent with
theoretical expectations, demonstrating the
law’s validity in a real world setting

10. Discussion
 1)Readings might not have been taken to eye level here while
measuring height.
 2)Reaction time added some flaws and uncertainity.
 3)Take minimum 3 reading of time from stop watch and then
calculate mean to minimize errors.
 4)As there are a lot of variables calculation should be done
carefully.
 5)The string wasn’t moving freely because of some frictional
problem.