• 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

Mechanics 2 Coursework - 'woosh' down the slide

Extracts from this document...

Introduction

Guowen Qin                                                                                                     2007-5-10

Mechanics 2 Coursework

‘woosh’ down the slide

Introduction:

The diagram below shows a slide. An object slides a distance L down the slide, and then shoots out at the end to fall through a vertical distance H before hitting the ground. Obviously, the greater L the further the horizontal distance D that it lands away from where it left the slide.

image00.pngimage01.png

image00.pngimage11.png

image12.pngimage13.png

Limage14.png

Өimage00.png

image26.pngimage03.pngimage27.pngimage02.png

image04.png

                                                          H            Plastic boximage05.png

image06.png

Dimage07.pngimage08.pngimage10.pngimage09.pngimage09.png

To investigate how D is related to L for one particular angle of inclination, I am going

to do an experiment to see if this relationship turns out in practice to be as predicted.

The apparatus that is required is:

  • A Wood ramp(slope);
  • A Aluminium weight(cube);
  • A plastic box;
  • A piece of card board;
  • A meter rule;
  • A protractor

Before I do the experiment, I need to make some assumptions which are relating to both the model and the experiment:

When the experiment is conducted, it must be insured that all of the apparatus is attached securely to ensure that nothing comes apart. General laboratory rules must be recognised to ensure safety throughout.

The variable that will be investigated is the range that the object is projected.

The independent variable is the height up the slope that the block is released from. It is measured using a metre ruler.

...read more.

Middle

image04.png

vvv

                                                           Himage05.png

image06.png

Dimage08.pngimage07.pngimage09.pngimage09.pngimage10.png

vh = vcosӨ ;    vv = vsinӨ

∵ D = vh * t     ∴ t = D / vh

Consider the vertical component,

S = ut + ½ ut2→ H = vv t + ½ gt2

→ H = vv D / vh + ½ g D2 / vh2

→ H = vsinӨ D/ vcosӨ + ½ g D2 / v2cos2Ө

→ H = D tanӨ + g D2 / (2 cos2Ө(2gL(sinӨ - tanФcosӨ)))

→ H = D tanӨ + D2 / (4 cos2ӨL(sinӨ - tanФcosӨ))

→ D2 / (4 cos2ӨL(sinӨ - μcosӨ)) + D μ - H =0

(Noticed that, this is a quadratic equation.)

I can calculate the horizontal distance D by substitute the Ө and Ф values in then solve the quadratic equation. This will give me the predicted value of D.

Let 1/(4 cos2ӨL(sinӨ - μcosӨ))=a; μ= tanФ =b; -H=c

The quadratic equation becomes aD2 + bD +c = 0 .

I will produce a table in Microsoft Excel, showing the Ө in degrees, Ф in degrees, L in metres, H in metres and a, b and c.

Then as long as I got the values for a, b and c, because it is a quadratic equation, so I will be able to calculate the value of D by using a formula to find the roots of a quadratic equation:-  (-b±(b2-4ac)^(1/2))/2a.

And in this case, I will only need the positive solution of the quadratic equation, which will be give by using the formula (-b+(b2-4ac)^(1/2))/2a.

...read more.

Conclusion

°(22.2-18.7), so the percentage error is roughly (3.5/20.4 *100%) 17.2%. It is a huge percentage error. Not only the error in reading the angle, but also the calculation μ = tan Ф, because the angle is in decimal place(not accurate), take the tangent to that angle will increase the error again. If the value of μ is not accurate, then the friction is not perfect as well, from the energy transfer equation, Ept = Epb + Ekb + W.D, the kinetic energy I obtained will be affected by the varied friction, the velocity when the block just leave the slope will change, therefore the distance land will vary.

e.g if the calculated μ is less than the actual value, the work done due to friction is smaller, so the velocity is greater than the actual value, then the landed distance obviously would be further away from the edge than the real landed distance. The graph for this case should lie a bit higher than the true graph.

Percentage error:

The error for the experiment caused by lots of things. Friction measurement, height measurement, length measurement and distance measurement.

Take the accuracy of each measurement and divide by the smallest value I have got for each measurement then times 100% to get the percentage error

The error for angle (Friction): 17.2%

After doing the calculation ,μ = tan Ф, the error increased.

The error for L (Length): image30.png0.001m

Percentage error =  0.001/0.1 * 100% =1.0%

The error for H (Height): image30.png0.001m                  

Percentage error =  0.001/0.282 * 100% =0.4%

The error for D (distance): image30.png0.001m

Percentage error =  0.001/0.129 * 100% =0.8%image31.png

Total percentage error = 17.2% + 1.0%+0.4%+0.8% =19.4%

/

...read more.

This student written piece of work is one of many that can be found in our GCSE Forces and Motion 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

See related essaysSee related essays

Related GCSE Forces and Motion essays

  1. Investigation into Friction.

    x 100 = 21 Therefore, 21 % is the maximum percentage error for the results for the rough hardboard experiment. This percentage error is relatively large, and this shows that the results that were obtained from the rough hardboard experiment are not as accurate as the ones from the smooth hardboard experiment.

  2. Investigating Sliding Friction: the effect of weight on sliding friction between a block and ...

    C stands for the frictional force present on the block even when there are no weights on top of it. This force is here because the block still has weight even though there are no weights on top of it.

  1. In this experiment I aim to find out how the force and mass affect ...

    SKILL AREA A : ANALYSING EVIDENCE AND DRAWING CONCLUSIONS Primary Experiment The graph clearly shows the increase in speed as the height of the ramp greatens, but not in a proportional manner. The slight curve suggests that another force is acting on the trolley and not permitting it to increase speed uniformly.

  2. The aim of this experiment is to investigate the relationship of the height of ...

    Since the motion of the drop of the metal ball should be the same (theoretically, when air resistance is the same), the effect of h2 will have no effect to the horizontal motion. As h2 gets bigger, the time it takes the metal ball to travel in the air is longer and therefore, a longer distance should be travelled.

  1. The Flywheel as an Alternative Energy Storage Device for Electric Vehicles (EV): Problems Associated ...

    In simpler terms, we have to maximize the strength to density ratio. The maximum energy stored However, it might seem like equation 1 does not justify the fact that we have to maximize the strength to density ratio. Since KE = 1/2I2, it seems that increasing the density would also increase the moment of inertia (since = m / V).

  2. Physics Coursework: To investigate the Oscillations of a mass on a spring

    As you can see, it is now a common sense that as the number of springs gets higher, the lower the frequency (number of oscillation in a given time), and as the number of springs gets fewer, the higher the frequency.

  1. Parachutes Coursework

    some parachutes were dropped from different heights then the ones that were dropped from higher hights would take longer to get to the ground than ones dropped from lower hights because they would have a longer distances to travell. Dropping the parachutes from the ceiling will be easier because then

  2. Resistance coursework

    Another thing I will need to find is the best meter, one which gives the most accurate reading, is easy to read and doesn't keep fluctuating. Also I need to find the correct voltage, this is so that the wire doesn't heat up, as this will heat up the wire

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