• 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.

    error if point is above line of best fit: plotted point - point on line of best fit = distance out distance out � point on line of best fit x 100 = percentage error The point on Graph 1 that has the greatest percentage error is the 13.28 N reading.

  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 ...

    ? How many results I will take ? What range of variables I will experiment with Safety With this straightforward experiment there is not much that needs to be taken into consideration. No harmful substances are being used, neither are flames, solvents, atomic-reactors or insurance salesmen so all-in-all a relatively safe experiment.

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

    Books and magazine Boxes Prediction: Since I am using h2 as the variable, I will measure it from the point of the metal ball leaving the ramp. I predict that the bigger the h2 is, the further the ball will travel.

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

    3rd experiment apparatus List: 1. Springs (Up to 7 springs) 2. Stand and Clamp 3. 4N of Mass (Load) 4. Stopwatch Diagram of the Apparatus: This experiment was to see whether the number of springs actually affected the time of oscillations.

  2. Motion of an object as it slides down a slope at different angles to ...

    This is to simplify the calculation too. In order to reduce systematic errors, I have also set a few rules about the setting up of the equipment and how to measure: * The measurements will be made to the nearest mm.

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

    The stress on the particles of the flywheel increases directly with the flywheel's spinning velocity4. Therefore, when a certain speed is reached, the tensile stress on the flywheel would exceed the tensile breaking stress of the material, and consequently, the flywheel particles would fly off in a straight path, tangential

  2. Physics Coursework

    The distance of the car is affected by the gravitational potential energy, which then changes into kinetic energy, the friction and the work done of the car. As the car comes down the ramp it should keep on gaining more and more speed due to the gravitational potential energy that the car has until it reaches its terminal velocity.

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