• 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

# The aim of this experiment is to test whether or not a Crunchie bar could be used as a bone replacement.

Extracts from this document...

Introduction

## Wendy Croft 12NB

Crunchie Bones?

The aim of this experiment is to test whether or not a Crunchie bar could be used as a bone replacement. If this were possible the crunchie would have to be strong enough to support the patients life style. The Crunchie bar will be used to replace a leg bone. After the experiment I will calculate the ultimate breaking stress of the Crunchie and then compare this to the ultimate breaking stress of a leg bone. I will calculate the stress by using the formula:

The apparatus is going to be set up as follows:

I will tighten both of the G-clamps by 90  at the same time, then I will read off the force on the dial of the scales. I will read the dial from directly above otherwise parallax may occur. I am using three crunchies at the same time, as this will be more reliable. To make

Middle

## Calculations

By doing the following calculations I will determine the ultimate breaking stress of the crunchie bars for one leg.

Stress (     ) = force (f)

Area (A)

Stress (     ) = 1190.0 N

0.0105 m

Stress (     ) = 113333.3 Pa

= 11 x 10    Pa

Due to inaccuracies of the scales I am going to calculate the maximum and minimum values of the force and then calculate the breaking stress due to these differences.

Maximum force = 1200 N

Minimum force =  1180 N

Maximum Stress = 1200 N

0.0105m

= 114285.7 Pa  (1dp)

= 1.14 x 10   Pa

Minimum Stress = 1180 N

0.0105m

= 112380.9 Pa (1dp)

= 1.12 x 10  Pa

I have accounted for the inaccuracies of the scales and of the turning of the G-clamps by drawing error boxes on the graph. The size of the error boxes is 20N x 36  .

Further calculations will determine whether or not the crunchie bar would be a suitable replacement for a leg bone.

Average mass of human = 60kg

Weight = mass x gravity

= 60 x 9.8

= 588 N

Conclusion

Area of both legs = 60 x 10  m                Area of crunchies = 0.0105m

Calculations for bone:                             Man lands on two legs = 0.0105 x 2

Stress = F                                                                          = 0.021m

Stress =  F

### =  3.80 x 10    N                                                                A

60 x 10    m                                                 = 3.80 x 10   N

=  6.3 x 10   Pa                                                        0.021m

= 18095238.1 Pa

= 1.8 x 10   Pa

These calculations show that the crunchie bar could not with stand the stress when the patient moved. This is shown in the calculations because the value of stress on the crunchie bars when put in this situation is greater than that of the leg bones. Therefore the crunchie bars would break.

Overall this experiment has shown that a crunchie bar could not be used as a suitable bone replacement as it would not be able to with stand the ultimate breaking stress of a person if they were standing still or if the person was moving.

If I had more time to continue this experiment I would make a piece of apparatus, like a protractor, that enabled me to measure the degree turns that I made when turning the G-clamps making my measurements more accurate. Using the apparatus I could also make more turns such as 45   turns as well as 90   turns.

This student written piece of work is one of many that can be found in our AS and A Level Mechanics & Radioactivity 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 AS and A Level Mechanics & Radioactivity essays

1. ## Use of technology in a hospital radiology department. The department of imaging is one ...

o Receptionist: - in the radiology department there are receptionist how are responsible for answering telephone, arranging patient appointment and calling patient from the waiting room when it is their turn to be seen. [14] M3 In UCHL hospital productive department contribute the service directly to the aim of the

2. ## The physics involved with a rollercoaster.

A straight ramp gives the rider a fast safe feeling ride. To give a rider more of a thrill, see the diagram below. The only problem with the diagram above is the impact with the ground. When the object slides down the curve, it has a great Vy.

1. ## Investigating the factors affecting tensile strength of human hair.

if I had waited for the hair to stretch, very slowly until it broke. There needed to be a time limit in which I had to record the extension of the hair, before adding the next weight to the hair. * The eye piece graticule can be a limiting factor.

2. ## Objectives: To determine the center of gravity of a body of irregular shapes

Firstly, we assume that there is no air movement during the experiment. If there is air movement, it will cause the board to move. It results in the incorrect position marked of intersection points on the paper and hence incorrect center of gravity marked on the paper.

1. ## Serving Newton

Law 11. The alteration of motion is ever proportional to the motive force impressed; and is made in the direction of the right line in which that force is impressed. Law 111. To every action there is always opposed an equal reaction; or the mutual actions of two bodies upon each other are always equal, and directed to contrary parts.

2. ## The Physics of an Atomic Bomb

is 2 MeV. A breakdown of the energy released by fission is given below: MeV Kinetic energy of fission fragments 165 +/- 5 Instantaneous gamma rays 7 +/- 1 Kinetic energy of neutrons 5 +/- 0.5 Beta particles from product decay 7 +/- 1 Gamma rays from product decay 6 +/- 1 Neutrinos

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