• Join over 1.2 million students every month
• Accelerate your learning by 29%
• Unlimited access from just £6.99 per month
Page
1. 1
1
2. 2
2
3. 3
3
4. 4
4
5. 5
5
6. 6
6
7. 7
7
8. 8
8
9. 9
9
10. 10
10
11. 11
11

# Objective To measure the centripetal force for whirling a mass round a horizontal circle and compare the result with the theoretical value given by F= mw2r .

Extracts from this document...

Introduction

 School: Canossa College Class: 6B Name: Hazel Chow Ho Ying Class no: 3 Date: 20-10-2010 Mark:

Title

Centripetal force

Objective

To measure the centripetal force for whirling a mass round a horizontal circle and compare the result with the theoretical value given by F= mω2r .

Apparatus

• rubber bung
• glass tube
• screw nuts
• Wire hook
• 1.5m of Nylon string
• Small paper marker
• metre rule
• stop-watch

Theory

When a mass m attached to a string is whirled round a horizontal circle of radius r, the centripetal force for maintaining the circular motion is given by

F = mω2r   where ωis the angular velocity of the circular motion.

This force is provided by the tension of the string.

The formula can also be expressed in the terms of the velocity v of the mass, where ω=v/r .

Substituting ω=v/r into the formula for F , F = mv2/r

Middle

Time 50 revolutions of the bung and calculate the angular velocity ω.Repeat several times using different lengths L of the string.

Result

Tabulate the results as follows:

Mass of rubber bung m =   0.03491   kg

Mass of screw nuts M =   0.13   kg

Tension in string T = Mg =   0.13   × 9.8 N =   1.274   N

 Length of string L/m 0.35 0.5 0.75 0.9 Time for 50 revolutions 50 t/s 30.85 37.04 45 49.65 ω = /rad s–1 10.183 8.482 6.981 6.327 mω2L/N 1.267 1.256 1.276 1.258

Mean mω2L =   1.264   N

Conclusion

Form the results, we can find that the length of the string L is increasing, the value of angular velocity ω is decreasing. The length of the string is indirectly proportional to the value of angular velocity.

Conclusion

ω2L .

They are almost equal.

Possible sources of errors

1. Friction exists between the glass tube and the string.
2. The rubber bung is not set into a horizontal circular path.
3. The rubber bung does not move with constant speed.
4. The length of the string beyond the upper opening is not constant.

θ increases with ω

Vertical components is T cosθ

Horizontal components is T sinθ

The system has no vertical acceleration

T cosθ = mg

The horizontal component of tension provides the centripetal acceleration

T sinθ = mrω2

Let L be the length of the string

i.e.  r = L sinθ

T sinθ = mrω2

T sinθ = m(L sinθ)ω2

T = mLω2

mg/cosθ= mLω2

θ increases with ω

When the rubber bung is whirled around with a higher angular velocity ω , the angleθ becomes larger.

Reference

1. Level practical physics for TAS p. 28 - 30
2. Physics Beyond 2000 p. 40
3. http://en.wikipedia.org/wiki/Centripetal_force
4. http://www.greenandwhite.net/~chbut/centripetal_force.htm

This student written piece of work is one of many that can be found in our AS and A Level Mechanics & Radioactivity section.

## Found what you're looking for?

• Start learning 29% faster today
• 150,000+ documents available
• Just £6.99 a month

Not the one? Search for your essay title...
• Join over 1.2 million students every month
• Accelerate your learning by 29%
• Unlimited access from just £6.99 per month

# Related AS and A Level Mechanics & Radioactivity essays

1. ## Centripetal motion. The objective of this experiment is to verify whether the tension ...

The hanger was first loaded with M = 150g. 3. The position of the paper clip was fixed about 1cm below the lower end of the glass tube by using adhesive tape. The rubber bung was kept about 80cm (l)

2. ## Young's Modulus of Nylon

and strain applied to it, as the material will be taken to breaking point, which could result in the material whipping back very quickly at this point, posing an eye damage hazard. It is also worth noting that at this point a substantial amount of weight will be dropping so

1. ## Science Coursework - Investigating How Mass Influences Distance Travelled When Firing A Margarine Tub.

From this research I have produced a predicted graph as shown below of stopping distance v mass. Equipment * Electronic balance (accuracy of 0.01 grams) * Margarine Tub * Meter ruler * Sand (& a spoon to measure it out).

2. ## Drayton Manor Theme Park: Centrepedial Force

The inertia in regards to circular motion is also known as centrifugal force, it is this that holds the passengers of cyclone in place.4 2nd Aspect of Physics -microgravity on the ride Apocalypse. When going on Apocalypse you have to stand on a platform and an attendant comes round a

1. ## The physics involved with a rollercoaster.

"Phrases like, '...slow down..., ...speed up..., ...change speed... and change velocity...'are used to describe acceleration" (According to General)The cars are pulled by a chain to the top of the highest hill along the track. Then they are released from the chain. As the front car begins its decent, the unpowered cars have almost no speed and only a small acceleration.

2. ## Find out the difference in flight time, of a weighted paper helicopter, on comparison ...

Increased cross-sectional areas result in an increased amount of air resistance. I think when there's more paperclips (when the helicopter is heavier) its time of fall would decrease. I think this will happen because the force pulling the helicopter down (weight/gravity pull)

1. ## Investigating the depression of a ruler when force is applied.

This is because there is more weight on the end of the ruler and therefore a greater gravitational force pulling down on the ruler. In scientific terms, I predict that the weight in Newtons will be proportional to the bend in the ruler.

2. ## The Physics of an Atomic Bomb

A similar approach is to use the implosion to initiate a neutron generating fusion reactions with tritium and deuterium. It may seem surprising that this can be made to work, given the well known fact that fission explosions are required to produce the temperatures that fusion reactions normally need.

• Over 160,000 pieces
of student written work
• Annotated by
experienced teachers
• Ideas and feedback to