Work and refrigerator energy

In summary, a mover is using a dolly to deliver a 110 kg refrigerator up a ramp with a length of 2.1 m and a rise of 0.42 m. The mover exerts a constant force of 445 N and the dolly and ramp together form a machine. To calculate the work done by the mover, the formula W=F*x is used, resulting in a final answer of 953.007 J. However, this answer was incorrect and further help is needed to understand the mistake.
  • #1
glasshut137
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Homework Statement



A mover's dolly is used to deliver a refrigerator up a ramp into a house. The refrigerator has a mass of 110 kg. The ramp is 2.1 m long and rises 0.42 m. THe mover pulls the dolly with constant velocity and with a steady force of 445 N up the ramp. The dolly and ramp constitute a machine. g=9.81/s^2

What work does the mover do?


The attempt at a solution

well i thought that this was a simple question. I used W=F*x using 445 N as F and 2.14 M as x which i got from using the pythagorean theorem. My final answer was 953.007 J but it was incorrect. Can someone help me understand what I'm doing wrong?
 
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  • #2
You are told that the ramp is 2.1 m long. The ramp is not lying on the ground! The ramp is the hypotenuse of the right triangle. Looks to me like you should just have 445*2.1!
 
  • #3


Your approach is correct, but there are a few things to consider. First, make sure you are using the correct value for the height of the ramp. The given height of 0.42 m is the vertical height, but you need to use the length of the ramp (2.1 m) as the distance. This is because the work done by the mover is in the direction of the ramp, not just the vertical direction.

Secondly, make sure you are using the correct value for the force. The problem states that the mover pulls with a steady force of 445 N, but this is not the same as the weight of the refrigerator (110 kg * 9.81 m/s^2 = 1079.1 N). The force of 445 N is the net force needed to overcome the force of gravity and move the refrigerator up the ramp with constant velocity. So, your calculation should be W = 445 N * 2.1 m = 934.5 J.

Lastly, make sure you are using the correct units. The work done should be in joules (J), not newtons (N). So, your final answer should be 934.5 J.

In summary, the work done by the mover to move the refrigerator up the ramp is 934.5 J. This work is equal to the force applied (445 N) multiplied by the distance moved (2.1 m), in the direction of the ramp.
 

What is the relationship between work and refrigerator energy?

The work done by a refrigerator is related to the energy it consumes. The refrigerator uses energy to compress the refrigerant and circulate it through the system, which in turn cools the inside of the refrigerator. As more work is done by the refrigerator, more energy is consumed.

How does the efficiency of a refrigerator affect work and energy consumption?

The efficiency of a refrigerator is directly related to its work and energy consumption. A more efficient refrigerator will require less work to be done and will consume less energy. This is because a more efficient refrigerator will be able to cool the inside with less energy input, resulting in lower work and energy consumption.

What is the impact of the temperature difference on the work and energy consumption of a refrigerator?

The temperature difference between the inside and outside of a refrigerator has a significant impact on its work and energy consumption. The greater the temperature difference, the more work and energy is required to keep the inside of the refrigerator cool. This is why it is important to keep the refrigerator in a cool environment and not place it near a heat source.

Can the size and type of refrigerator affect its work and energy consumption?

Yes, the size and type of refrigerator can have an impact on its work and energy consumption. A larger refrigerator will typically require more work and energy to cool the larger space. Additionally, the type of refrigerator (e.g. top freezer, side-by-side, etc.) can also affect its energy consumption. It is important to consider the size and type of refrigerator when trying to reduce work and energy consumption.

What can be done to reduce the work and energy consumption of a refrigerator?

There are several steps that can be taken to reduce the work and energy consumption of a refrigerator. These include keeping the refrigerator in a cool environment, not overfilling it, and regularly cleaning the coils to ensure optimal efficiency. Additionally, purchasing a more energy-efficient refrigerator can also help reduce work and energy consumption in the long run.

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