• 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

# Making sense of data.

Extracts from this document...

Introduction

Coursework - Making Sense of Data

Introduction

The method used to collect the data was to fire projectiles from a launcher into a sandpit. The distance the projectile travelled was measured. For each projectile the angle of the launch was varied from 15 to 70o, from the horizontal. Twelve different angles were tested and three repeat readings were taken at each angle.

Five ball bearings with different diameters were used. The ball bearing was fired using a spring mechanism into a sandpit, which was at the same height that the ball bearing was launched from. The distance travelled was measured using a meter ruler.

Apparatus Diagram

Plan

• From the raw results the mean distance travelled was calculated, giving an average reading using all the data.
• From the diameter of the ball bearing the volume of the ball bearing was calculated - 4/3 * pi * radius3.  From this the mass can be calculated (using mass = density * volume).
• The energy the spring provided was given as 0.1J. Using the mass this allowed the initial velocity to be calculated (initial velocity =sqrt (KE/0.5m)).
• The initial velocity was divided into horizontal and vertical components using the sine and cosine rules combined with the angle of launch.
• Knowing that the displacement vertically is zero, gravity is -9.8N/Kg and the initial vertical velocity the flight time can be worked out: time=2(initial velocity/gravity).
• Assuming no air resistance the distance traveled should equal the time taken multiplied by the initial horizontal velocity. This allows a theoretical prediction of the distance travelled, which can be compared to the actual distance measured.

Middle

θcosθ
 This graph should also fall on a straight line. This is because U2 = (2*kinetic energy)/mass and by substituting it into the equation from graph 2 you get:                   S =       (4Ke)        * sinθcosθmass *gravityTherefore plotting S(y) and 1/mass (x) the gradient will be     4ke     *  sinθcosθ,         GravitySo if the angle remains constant the gradient will be constant, giving a straight line.

3. Distance-1/mass

e.g.

1/mass

4.  Estimated distance and actual distance against angle for a given diameter of ball bearing

This graph will show the difference between the actual results and the calculated distance using the energy (0.1J). It will be useful because, if the energy is correct, it will show how other factors including air resistance and measuring errors affect the results. Therefore the figures for estimated distance will probably be larger, i.e. the curve will be above the actual results as there is no air resistance.

Sample calculation

 Launch Angle (o) Angle (r) Diameter of ball bearing(m) Distance 1(mm) Distance 2(mm) Distance 3(mm) 15 0.26183 0.01 1395 1412 1418

Using the result:

1. Average distance = (1395+1412+1418)/3 = 1408.3mm
1. Volume of ball bearing = [4/3*Pi*r3]

= 4/3 * 3.142 * (0.01/2 – radius)3

= 5.24E-07

1. Mass of ball bearing     = density * volume

= 8020 * 5.24E-07 = 0.004Kg

1. Initial Velocities=
•  Initial velocity = √(0.1/0.5*0.004) = 6.9ms-1
•  Initial velocity vertically = 6.9 * sin0.262 = 1.786 ms-1
•  Initial velocity horizontally = 6.9 * cos0.262 = 6.666 ms-1

Conclusion

o and then decreasing again. However the actual distances are below what was expected. This may have been due to a number of factors (described below) or air resistance, which caused drag on the projectile, reducing its horizontal velocity.

Errors

All the measurements recorded have a small degree of inaccuracy. For example, the distance the projectile travelled was measured with meter rulers to the crater formed in the sandpit, and the accuracy of this measurement is about +/- 1-2mm. This would not affect the results considerably as it is only a small percentage error - 2/2000 = 0.1%. Other small inaccuracies may have occurred with measuring the diameter of the ball bearing (+/- 0.1mm), adjusting the launch angle (+/- 0.5o) and aligning launcher at the same height as the sandpit (+/- 2mm). I feel the biggest error was in measuring the energy of the spring. This is probably why the calculated distance the ball bearing should have travelled is a lot further than the actual distance travelled. If this was the correct energy

provided by the spring air resistance would have reduced the distance travelled by almost 50%! (2380/4859*100 = 49%). Considering the experiment was conducted in a classroom without any wind this seems a very large value.

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

# Related GCSE Forces and Motion essays

1. ## Investigating the amazingness of theBouncing Ball!

From my graph it's been found that y=2.5 x - 0.24 18 So ?= 2.5 = 0.14(2dp) 18 Though the coefficient of restitution and the deacy constant will be achieved from analysing the same bit of data they will not be dependant on each other ie.

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

Obviously we will need to take precautions when increasing the mass of the trolley and make sure that all the weights are securely fixed to it by using sellotape, string etc. Especially when the trolley reaches high speeds, the likelihood of weights falling off is increased and this could be potentially harmful to an innocent on-looker.

1. ## Mechanical Properties of a Meter Rule

* The same rule will be used throughout the experiment, so that mass and width etc. will remain constant. * Displacement of the pendulum: This will remain constant at 0.20 meters. * Air resistance: It is assumed that there is no air resistance and 100% of gravitational potential energy is converted to kinetic energy, and vice versa.

2. ## Approximate Stopping Distances

Braking distances are not directly proportional to speed unlike thinking distances which are directly proportional to speed. The braking distance increases massively as the as the speed of the vehicle increases. For example if the vehicle is travelling at 30 mph the braking distance is 45 ft and when the

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

anymore for each experiment. So by looking at the results, my hypothesis about the amplitude was wrong, because I said that the amplitude does affect the time of oscillation, but actually, it doesn't. The prediction that is stated above is based on many experiments carried out previously, including the trial experiment for this investigation

2. ## Making Sense of Data.

velocity at the start of the ramp than at the end, which can be seen due to the fact that the gradient becomes shallower. This must mean that there is a larger force opposing the trolley as it picks up speed and could be due to air resistance.

1. ## Designing a children's slide, making it exciting for the children whilst exercising safety.

F = friction force (Newton) N = normal contact force M = being the mass G = the gravitational pull i.e. 9.8mg/s2 F = mg sin ? N = mg cos ?

2. ## Experimental Techniques; Analysis of Boundary Layer Data.

0.0251 0.152747 0.59065 0.462601881 0.5 0.5374 0.28928693 0.248601381 0.12106535 0.0334 0.151193 0.61543 0.517238474 0.5 0.48276 0.25503991 0.249702835 0.12457605 0.0418 0.145951 0.63536 0.567915838 0.5 0.43208 0.22871142 0.245387439 0.12377257 0.0502 0.139529 0.65213 0.599502832 0.5 0.4005 0.20814533 0.240099186 0.12137166 0.0585 0.129714 0.66665 0.615678193 0.5 0.38432 0.19620474 0.236618556 0.11917944 0.0669 0.125845 0.67948 0.61744223 0.5

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