# I am going to investigate the effect of how friction acts on a cylinder rolling across a carpet after going down a ramp at a selected angle.

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Introduction

Viren Shah GCSE Physics coursework – Cylinder going down a ramp.

PH10Y1

## What is there to investigate?

I am going to investigate the effect of how friction acts on a cylinder rolling across a carpet after going down a ramp at a selected angle.

Here is a diagram of the apparatus that I will use:

## Apparatus (The set-up of the items that I’m going to use)

## What it all means and what I will need to measure

Cylinder 1,2 and 3 represent one cylinder at different stages. Cylinder 1 is the starting point of the cylinder. Cylinder 2 is just before the cylinder goes onto the carpet. Cylinder 1’s Potential Energy and Cylinder 2’s Kinetic energy are the same value. Cylinder 3 is where the Cylinder has stopped. I will measure the distance that the Cylinder has rolled from the carpet (d), after the Cylinder has left the ramp. I will also measure the height (perpendicular to the carpet) at which the Cylinder falls from. I may also need to measure the mass of the Cylinder. This will help us to work out the potential and kinetic energy. But I wont have to do this till a later stage.

However, I will not need to measure the angle of the slope, because that will always stay the same through out the test (We had to choose one of eight slots in which to put the ramp. If it did not stay the same, it would be an angle versus distance and we are trying to find out height (h) versus distance).

## Method

- I will set-up the apparatus how it is shown in the diagram.
- I make sure the carpet is right in-line with the ramp.

Middle

4.8

60

4.3

54

3.8

47

3.3

40

2.8

35

2.3

28

1.8

22

1.3

15

0.8

9

From the evidence I have obtained, I can see straight away that the higher the cylinder is up the ramp, the further the cylinder goes on the carpet. For every 0.5 of a centimetre the height increases, the height increases by 5, 6 or 7 (Average of 6.1666666666….).

The speed that the Cylinder rolls down the ramp at can be found by firstly finding the kinetic energy (KE). The KE at the bottom of the ramp is the same as the PE at the top of the ramp. The mass of the cylinder was 250g. The height of the ramp was 6.8 cm. The length of it was 55 cm.

KE gained = PE lost

PE lost = mgh.

PE lost =0.25 x 10 x .068

PE lost =0.17J

KE gained =0.17J

KE =½mv²

0.17J =½ x 0.25 x v²

0.17J =0.125 x v²

V² =0.17 / 0.125

V² =1.36m/s

V = 1.36

VELOCITY =1.1661m/s

The acceleration can be worked out: (v²=u²+2as)

(a=v²-u²)

2s

S (Distance) :0.55m

U (Initial velocity) :0

V (Final velocity) :1.16m/s

A (Acceleration)* :?

T (Time) :

*Where a is a constant

v²=u²+2as

- = 0 + 2(A x 0.55)

- = 2(0.55 x A)

a = 1.36 / 1.1

ACCELERATION = 1.2 m/s² (1d.p)

Now, we can now work out the deceleration on the carpet.

S:0.82m

U:1.16m/s

V:0m/s

A:?

T:

v²=u²+2as

0²=1.16²+ 2(82 x a)

0 =1.36 + 1.64a

-1.36= 1.64a

a = -1.36 / 1.64

DECELERATION = 0.8296m/s²

The time taken for the cylinder to roll between the foot of the ramp and the place where the cylinder stops can be worked out:

S:0.82m

U:1.16m/s

V:0m/s

A:0.8296m/s²

T:

S=½(u+v)t

0.82=½ x (1.16 +0)t

0.82=0.58t

t=0.82/0.58

TIME=1.413s

It takes the cylinder 1.413s to stop.

That is when the cylinder is released at 6.8cm high

When the same cylinder is released at 3.

Conclusion

- While one is releasing the cylinder on the ramp, he can inadvertently push or hinder the cylinder. Also, one may not place the cylinder on the ramp in exactly a straight line
- The distance is only measured to the nearest centimetre and is subject to rounding up or down
- The surface where the distance is measured may not be uniform so there is excessive or reduced friction.

I think the method I used was good because the graph shows an almost perfect fit.

It would be unlikely that these results would just be a coincidence.

### Conclusion

Through this evidence, a firm conclusion can be drawn, especially from the graph.

The higher the cylinder is dropped from, the further the cylinder rolls on the carpet. The evidence of this is firmly supported by the graph. The graph was a straight line going, (or very close to) through 0,0.

### Improvements

The follow improvements would be recommended:

- There should be a mechanism that holds the cylinder in place on the ramp, and at the intended height, the cylinder can be released without aiding or hindering it.
- The ground surface must be uniform.
- There should be a mechanism, which ensures that the cylinder is in a straight line at the release of it.
- A computerised device that measures the distance in millimetres, or even micrometers could measure the distance that the cylinder travels.
- The cylinder should be a perfect cylinder with perfect grooves or dents.

### Further work

One could:

- For each point on the ramp, repeat the experiment ten times, and then take the average.
- One could do the experiment with different sorts of cylinders

- Wooden cylinders
- Different metal cylinders
- Hollow cylinders
- Different sized cylinders

- One could repeat the experiment but instead of cylinders, one could use different spheres.

- -

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

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