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Homework Statement
I am doing a project on pressure sensitive films and finding if they indicate the correct amount of impact. I have carried out an impact test by dropping a mass of 5KG from a height of 1m. I have calculated the velocity to be 4.43m/s. The kinetic energy just before impact is equal to the gravitational potential energy at the height in which it was dropped =49J. The distance traveled after impact was 0.1m. Using the work-energy principle the impact force is found to be 490N.
The attempt at a solution
This test I used a hexagon shaped mass and the area which contacted the film was 116.63m^2.
The pressure film is indicating a pressure force of 6.5MPa=65kgf/cm^2.
The impact force that has been calculated is 490N=49.9kgf.
The calculated and indicated pressure forces can be seen to be far off. The manufacturer of the pressure film has claimed that the films give an estimated pressure and not necessarily exact.
I just want to ask if anyone sees where I am going wrong? I also want to ask if area needs to be considered in the calculation.
Thanks for your time.
Alexander.
I am doing a project on pressure sensitive films and finding if they indicate the correct amount of impact. I have carried out an impact test by dropping a mass of 5KG from a height of 1m. I have calculated the velocity to be 4.43m/s. The kinetic energy just before impact is equal to the gravitational potential energy at the height in which it was dropped =49J. The distance traveled after impact was 0.1m. Using the work-energy principle the impact force is found to be 490N.
The attempt at a solution
This test I used a hexagon shaped mass and the area which contacted the film was 116.63m^2.
The pressure film is indicating a pressure force of 6.5MPa=65kgf/cm^2.
The impact force that has been calculated is 490N=49.9kgf.
The calculated and indicated pressure forces can be seen to be far off. The manufacturer of the pressure film has claimed that the films give an estimated pressure and not necessarily exact.
I just want to ask if anyone sees where I am going wrong? I also want to ask if area needs to be considered in the calculation.
Thanks for your time.
Alexander.