Physics Practical

Physics Practical Chapter 4 Turning Effect of Forces

September 27, 2024
Urdu

4.3 Verify the Principle of Moments by Using a Meter Rod Balanced on Wedge

Observations and Calculations
Position O of center of gravity of meter rule=50cm

 

No Suspended
Weights		 Position Distance
from
center
of gravity
(moment
arm)
w1
N		 w2
N		 w3
N		 A
cm		 B
cm		 C
cm		 OA
cm		 OB
cm		 OC
cm
1 0.7 0.2 0.2 70 20 10 20 30 40
2 0.7 0.2 0.2 70 20 10 20 30 40
3 0.7 0.2 0.2 70 20 10 20 30 40

 

No Clockwise
moment		 Total
anticlockwise
moment		 Difference
of moments
τ1=w1xOA
Ncm		 τ2=
w2xOB+w3xOC
Ncm		 τ2-τ1
Ncm
1 14 14 0
2 14 14 0
3 14 14 0

Result
Difference of moments is equal to zero.

 

4.4 Find the Unknown Weight of an Object by Using Principle of Moments

Observations and Calculations
Position O of center of gravity of meter rule=50cm
Value of known weight=5N

No Position Distance
of
unknown
weight w1
from O		 Distance
of
unknown
weight w2
from O		 Unknown
weight of
object
w1
A
cm		 w2
B
cm		 a
cm		 b
cm		 w1=w2 x (b/a)
N
1 30 80 20 30 7.5
2 30 80 20 30 7.5
3 30 80 20 30 7.5

Result
Average value of weight w1= 7.5N
Measured weight of object w = 7N
Difference = w1-w = 0.5N

 

4.5 Find the Tension in Strings by Balancing a Meter Rod on the Stand

Observations and Calculations
Position O of center of gravity=50cm
Weight of the meter rod w = 10N

No Position Distance
of S1
from B		 Distance
of w
from B
A
cm		 B
cm		 a=AB
cm		 b=OB
cm
1 10 20 200 10
2 8 55 176 10
3 12 18 176 10

 

No Calculated
tension		 Readings
of spring
balances		 Difference
T1=w(b/a)
N		 T2=w[(a-b)/a]
N		 S1
N		 S2
N		 T1-S2 T2-S2
1 0.5 9.5 20 40 -19.5 9
2 0.56 9.4 22 42 -21.44 8.84
3 0.56 9.4 18 44 -17.44 8.84

Result
Difference is approximately 9.