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Urgent help required - My Internet is down

  1. Aug 15, 2013 #1
    I'm Kind of worried ..I am a poor Uni student and my net has been recently disconnected due to me not being able to pay the bill, I'm at an Internet cafe at the moment and I'm running out of money to stay here.

    I found out I have a physics home assignment due today (in about 6 hours) I know you're not meant to post like this but I really need help to get this assignment in by today. I will post all question up here ... I have done some already since I have been at the cafe.

    There is 30 questions I have 12-13 (I'm deleting questions as I do them) left to do I'll post them here and any help will be appreciated - I am not a bad student I'm just poor, and having no Internet at home is killing me.

    I will also be working though these questions myself but I only have enough money left for about an hour of cafe time ... please help me

    1. If the weight of the patient lying on a treatment or examining table is distributed onto a total skin area of 0.50 m2, what is the pressure being exerted on the skin? (Assume a simple model of uniform distribution of the body’s weight by the body parts bearing that weight.) (2 marks)

    2. When pressure sores develop from sustained positions, the damage occurs at two locations simultaneously – the superficial layers of skin next to the table, and the deep tissue next to the bony structure (e.g. lateral aspect of the femur) that the patient is lying on. What physics concept helps to explain this? Justify your answer. (3 marks)

    3. Explain how the addition of a pad on the hard examining table would reduce the risk of pressure sore development in the patient who is required to lie on it for a procedure. (2 marks)

    4. In many health centres, some inpatient beds have fluid-filled mattresses to minimise pressure ulcer development. What is the physics behind the use of a fluid-filled mattress? (3 marks)

    5. If the 50 kg patient is lying on a sheet on a gurney (stretcher), and you and a colleague must transfer the patient to an examining table, why is it better technique from a physics perspective to use a slow steady pull on the sheet to slide the patient across rather than a rapid jerk on the sheet? (3 marks)

    6. When assisting a very unsteady patient from a standing to sitting position on a chair, it is important to help the patient lower himself slowly onto the chair rather than to drop down by gravity alone. Why is the speed of the patient when reaching the chair significant to any resultant tissue damage? (3 marks)

    7. A new laboratory has been built with infection control in mind. The ceilings, walls and floors are made of hard smooth surfaces that are easy to clean. The walls are bare – no pictures or posters – and there are no open cupboards for storage, but instead there are built-in wall-to-wall cabinets with smooth surfaces to store. This new design is quite different from the old lab. After the staff move in their old equipment and start work in the new lab, they complain that the new lab is terribly noisy. Why does the staff find this new lab noisier, even though the equipment has not changed in its performance? (2 marks)

    8. While there is no objective measure for ‘noisiness’, there is a measure of sound level. If the new lab in the question above is found to be 20 decibels louder than the old lab, what is the increase in intensity of sound in the new workplace? (3 marks)

    9. Most electronic devices generate a significant amount of heat, but the electronics tend to be easily damaged by that heat. As a result, many electronic devices use cooling fans. To be effective, the fan has to prevent the device from reaching a temperature that would cause damage. Explain the physics of using the fan for cooling. (2 marks)

    10. Identify three factors that would impact the effectiveness of a cooling fan’s ability to prevent temperature rise (assuming the fan is operating properly). (3 marks)

    11. Within an x-ray tube, a metal disc (the anode) receives a huge amount of energy that is converted to internal energy (heat) within the anode. The surface temperature can easily reach 2000° C. Because the anode is within a vacuum and therefore there is no air around the anode, a cooling fan cannot be used. Many physics concepts are used to design the anode to minimize the temperature rise (to avoid reaching the melting point of the metal) despite all of the energy received. Identify any two possible physics concepts that could be used, and explain how each could minimize temperature rise. (4 marks)
  2. jcsd
  3. Aug 15, 2013 #2


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    Staff: Mentor

    You need to use the homework template and show your work and where you are having trouble with each problem. You cannot expect members to just guess where you need help. Surely you can go to a library and get free internet. This is not acceptable.
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