Do substances that heat up quickly have high or low specific heat capacity?

Determine the minimum work per unit of heat transfer from the source reservoir that is required to drive a heat pump with therma

Sloan [31]

Answer:

The minimum work per unit heat transfer will be 0.15.

Explanation:

We know the for a heat pump the coefficient of performance ( $C_{HP}$ ) is given by

$C_{HP} = \dfrac{Q_{H}}{W_{in}}$

where, $Q_{H}$ is the magnitude of heat transfer between cyclic device and high-temperature medium at temperature $T_{H}$ and $W_{in}$ is the required input and is given by $W_{in} = Q_{H} - Q_{L}$ , $Q_{L}$ being magnitude of heat transfer between cyclic device and low-temperature $T_{L}$ . Therefore, from above equation we can write,

$&& \dfrac{Q_{H}}{W_{in}} = \dfrac{Q_{H}}{Q_{H} - Q_{L}} = \dfrac{1}{1 - \dfrac{Q_{L}}{Q_{H}}} = \dfrac{1}{1 - \dfrac{T_{L}}{T_{H}}}$

Given, $T_{L} = 460 K$ and $T_{H} = 540 K$ . So, the minimum work per unit heat transfer is given by

$\dfrac{W_{in}}{Q_{H}} = \dfrac{T_{H} - T_{L}}{T_{H}} = \dfrac{540 - 460}{540} = 0.15$

8 0

3 years ago

In pushing a heavy box across the floor, is the force you need to apply to start the box moving greater than, less than, or the

Veseljchak [2.6K]

Answer:

Explanation:

Force needed to apply start the box is greater than the force needed to keep it moving because static friction is greater than the kinetic friction .

A threshold force is needed to move the box and when box started to move kinetic friction comes into play.

Friction force is directly related to the weight of the box as the friction force is

coefficient of friction time Normal reaction .

And Normal reaction is equal to the weight of box if no force is applied.

$f_r=\mu N$

$N=mg$

3 0

3 years ago

What are the things on top of the titanic called?

KengaRu [80]

Simple answer: they are like large chimneys for the fuel's excess gas.

6 0

3 years ago

Sarah is a forensic what is her job to do

Dominik [7]

Answer:

She takes pictures and analyzes DNA samples

5 0

3 years ago

Select ALL the correct answers. Two metal balls are dropped from the top of a two-story building at the same time. One ball is t

anastassius [24]

Statements 2 and 4 are correct. The velocity changes because the initial velocity is zero and each second they gain 9.8 m/s of velocity, which is the constant acceleration. Because there is no air resistance, they will land at the same time, and gravity acts equally upon both objects, so the velocity of both metal balls should always be the same.

6 0

4 years ago