Part of The Student Room Group

  • 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
  12. 12
    12
  13. 13
    13
  14. 14
    14
  15. 15
    15
    • View my saved documents

    Centripetal Force

    Extracts from this document...

    Introduction

    Centripetal Force

    Aim:

    • To investigate the relationship between the centripetal force action on an object moving in a circle of constant radius and the frequency of revolution.

    Hypothesis:

    The centripetal force of an object of mass (m) moving at a constant velocity (v) and radius (r) is given by ΣF = image00.png= 4π2rmf2. where:

    Fc is the centripetal force in N

    Fg is the force of gravity in N

    r is the radius of the string in m

    ms is the mass of the rubber stopper in kg  

    ml is the mass of the suspended load in kg

    g is the gravitation in m s-2

    From that equation, I can deduce that if the frequency of object spinning is increased, the centripetal force will increase. Also, in this experiment, the force of gravity acting on the suspended mass should be the one providing the centripetal force. This force is given by: image01.pngwhere in this case m is the mass of the suspended load and g is the gravity.

    Variables:

    Dependent

    Independent

    Controlled

    The period of the revolution measured by using stopwatch, the frequency and the centripetal force

    load mass (varied from 10 gr until 50 gr with interval 10 gr each)

    • The small of soft mass (rubber stopper)
    • horizontal string length

    Apparatus:

    Name

    Quantity

    Accuracy

    Thin plastic tube about 15 cm long, with no sharp edges

    1

    ±0.5cm

    1.5 of fishing line

    1

    -

    Paper clip

    1

    -

    Small soft mass (rubber stopper)

    1

    -

    Mass carrier and slotted masses (10 g each)

    As needed

    -

    Stop watch

    1

    ∆t ±0.005s

    Metre ruler

    1

    ∆l ± 0.5 cm

    Electronic Scale

    1

    ∆m ± 0.005 g

    Method:

    1. Securely tie one end of the fishing line to a small, soft mass.

            (Since this is going to be twirled around your head, make sure the mass isn’t too hard!).

    1. Pass the line down through a thin plastic tube and attach a 10 g slotted mass carrier to the end as shown in the diagram. Attach a paper clip to the line to act as a marker for a measured radius of around 1 metre.
    2. Add 10 g masses to the mass carrier to make a total mass of 20 g.

    image12.png

    1. Twirl the stopper in a horizontal circular path at a speed that pulls the paper clip up to, but not touching, the bottom of the tube.
    2. Get a partner to keep an eye on the position of the clip to ensure that the speed of rotation stays quite constant. Practise doing so for a while before trying any measurements.
    3. Maintain the speed of revolution and measure the time taken for 10 revolutions of the small mass.
    4. Add an extra 10 g to the mass carrier and repeat steps 2 and 3.
    5. Add another 10 g to the mass carrier and repeat steps 2 and 3. Keep adding an extra 10 g mass to the mass carrier.

    Data Collection:

    Radius of the string, r = 0.3 m

    Mass of the rubber stopper: m=0.0187 kg

    Table 3.1 Result of time taken for 10 revolutions for mass 10 g

    Trial

    Time Taken

    t(s)

    ∆t = ±0.005 s

    1

    8.00

    2

    7.47

    3

    7.49

    4

    7.09

    5

    7.16

    6

    7.25

    7

    7.45

    8

    7.22

    9

    7.49

    10

    6.78

    Table 3.2 Result of time taken for 10 revolutions for mass 20 g

    Trial

    Time Taken

    t(s)

    ∆t = ±0.005 s

    1

    6.47

    2

    7.47

    3

    6.91

    4

    7.44

    5

    7.00

    6

    7.32

    7

    6.35

    8

    7.50

    9

    7.79

    10

    8.47

    Table 3.3 Result of Time taken for 10 revolutions for mass 30 g

    Trial

    Time Taken

    t(s)

    ∆t = ±0.005 s

    1

    7.16

    2

    7.25

    3

    6.79

    4

    7.72

    5

    6.40

    6

    8.04

    7

    7.84

    8

    7.41

    9

    6.32

    10

    6.53

    Table 3.4 Result of time taken for 10 revolutions for mass 40 g

    Trial

    Time Taken

    t(s)

    ∆t = ±0.005 s

    1

    7.03

    2

    7.40

    3

    6.62

    4

    6.87

    5

    7.34

    6

    7.12

    7

    6.47

    8

    6.60

    9

    5.91

    10

    7.72

    Table 3.5 Result of time taken for 10 revolutions for mass 50 g

    Trial

    Time Taken

    t(s)

    ∆t = ±0.005 s

    1

    5.68

    2

    6.03

    3

    7.97

    4

    6.34

    5

    6.16

    6

    6.90

    7

    7.59

    8

    6.81

    9

    7.78

    10

    6.67

    ...read more.

    Middle

    6.78

    0.678

    1.474926

    2.175407

    0.481308

    0.068510

    0.0046937

    ΣFc=

    4.127976

    image06.png

    0.0116417

    Average centripetal force:image34.png

    Standard deviation: image35.png

    So, the centripetal force of mass 10 g is:  image36.png

    Force of gravity with mass 10 g: image37.png

    image02.png

    image03.png

    Table 4.2 Data of Centripetal Force for mass 20 g

    Time for

    10 revolutions (s)

    Period

    (T/s)

    f = 1/T

    (Hz)

    f2

    Fc

    (N)

    image04.png

    image05.png

    6.47

    0.647

    1.545595

    2.388864

    0.528535

    0.101778

    0.0103587

    7.47

    0.747

    1.338688

    1.792086

    0.396498

    -0.030259

    0.0009156

    6.91

    0.691

    1.447178

    2.094324

    0.463368

    0.036611

    0.0013404

    7.44

    0.744

    1.344086

    1.806567

    0.399702

    -0.027055

    0.0007320

    7.00

    0.700

    1.428571

    2.040816

    0.451529

    0.024772

    0.0006136

    7.32

    0.732

    1.366120

    1.866284

    0.412914

    -0.013843

    0.0001916

    6.35

    0.635

    1.574803

    2.480005

    0.548700

    0.121943

    0.0148701

    7.50

    0.750

    1.333333

    1.777778

    0.393332

    -0.033425

    0.0011172

    7.79

    0.779

    1.283697

    1.647878

    0.364592

    -0.062165

    0.0038645

    8.47

    0.847

    1.180638

    1.393905

    0.308401

    -0.118356

    0.0140082

    ΣFc=

    4.267571

    image06.png

    0.0480119

    Average centripetal force:

    image07.png

    Standard deviation

    : image08.png

    So, the centripetal force of mass 20 g is:  image09.png

    Force of gravity with mass 20 g: image10.png

    image11.png

    image13.png

    Table 4.3 Data of Centripetal Force for mass 30 g

    Time for

    10 revolutions (s)

    Period

    (T/s)

    f = 1/T

    (Hz)

    f2

    Fc

    (N)

    image04.png

    image05.png

    7.16

    0.716

    1.396648

    1.950626

    0.431575

    -0.010600

    0.0001124

    7.25

    0.725

    1.379310

    1.902497

    0.420926

    -0.021249

    0.0004515

    6.79

    0.679

    1.472754

    2.169004

    0.479891

    0.037716

    0.0014225

    7.72

    0.772

    1.295337

    1.677897

    0.371234

    -0.070941

    0.0050326

    6.40

    0.640

    1.56250

    2.441406

    0.540160

    0.097985

    0.0096011

    8.04

    0.804

    1.243781

    1.546991

    0.342271

    -0.099904

    0.0099807

    7.84

    0.784

    1.275510

    1.626926

    0.359957

    -0.082218

    0.0067598

    7.41

    0.741

    1.349528

    1.821225

    0.402945

    -0.039230

    0.0015390

    6.32

    0.632

    1.582278

    2.503605

    0.553921

    0.111746

    0.0124872

    6.53

    0.653

    1.531394

    2.345166

    0.518867

    0.076692

    0.0058817

    ΣFc=

    4.421747

    image06.png

    0.0532685

    Average centripetal force :

    image14.png

    Standard deviation:

    image15.png

    So, the centripetal force of mass 30 g is:  image16.png

    ...read more.

    Conclusion

    There will be some improvements in this experiment that I need if I’ll do this experiment again. First of all we need to practice to swing it horizontally, and when we want to record the revolution after 10 swings, we must carefully count the revolution because sometimes our eyes can’t follow the revolution. Secondly, we also need  more careful when swing because sometimes the mass can contact our head or our friends. I also need to keep the string is not moving so that the length can be measured perfectly. To get more accurate results, we can also give an alternative independent variable such as the length of the string. By getting the results from the different mass and different length of string it will make the data more accurate to prove the theory and hypothesis.

    ...read more.

    This student written piece of work is one of many that can be found in our International Baccalaureate Physics section.

    Found what you're looking for?

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

    or


    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

    See related essaysSee related essays

    Related International Baccalaureate Physics essays

    1. Analyzing Uniform Circular Motion

      That was not possible due to the slightest of air resistance. The horizontal component labelled as r would be known as the radius since the mass spins at an angle from the horizontal. This however is hard to measure and thus is assumed to be constant.

    2. Investigate the factors affecting the period of a double string pendulum

      Another major limitation to my experiment was my human reaction time and speed on counting the number of waves and pressing the 'stop' button on the digital timer after counting 10 waves.

    1. Suspension Bridges. this extended essay is an investigation to study the variation in tension ...

      Using the formula for Tension as derived in the last section, I have also calculated the tension T1 existing in the left part of the string. Sample Calculation of Tension T1 When the length of the string = 140 cm and the point of application of force 'x' cm =

    2. The Affect of Mass on the Time It Takes an Object To Fall

      not a power function, but rather a linear equation, poses the question as to why the square root of mass had to be taken to linearise the data. We believe that our data was changed more by random error than systematic error.

    1. Finding the Spring Constant

      N/m --> this was gotten from our previous lab where we had to find the spring constant) as it was just a bit off. Since the two values are positively correlated, the time is proportional to the mass (T�? m), thus this illustrates that the spring takes quite a long time to complete one whole oscillation.

    2. Circular Motion Practical - The graphs show that there is a positive correlation between ...

      Yet for both graphs the line should cut through the origin. For test one instead of cutting through the origin, the line has a y-intercept of around 1.3.This is obviously ridiculous as it is suggesting that when there is the force is 0N, the object will is rotation at 1.3ms^-1, and thus accelerating constantly.

    1. The weakest force of the universe

      The strong force also acts between protons and neutrons in an atomic nucleus much in the same way that simple chemicals are held together by the electric force. The strong force binds the two protons with about 25-35 MeV of energy.3 The body of data describing the strong force between

    2. The Affect of Mass on the Period

      Raw Data and Accompanying Graph: Constant String Length: 34.0cm � 0.2cm Constant Release Point: 45o � 1o Period (s) Mass (g) Mass Uncertainty (�g) Trial 1 Trial 2 Trial 3 Trial 4 Trial 5 Uncertainty (�) 20.0 0.2 1.0 1.0 1.1 1.1 1.1 0.1 50.0 0.2 1.1 1.0 1.1 1.1

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