Hydrogen fuel cells is the answer
Answer
A. the work done on the refrigerant in each cycle is 105kJ
B the coefficient of performance of the refrigerator is 4.8
Explanation
Given data
Work done at high temperature T2 Qh=610kJ
Work done at low temperature T1 Ql=505kJ
We know that the net work done by the refrigerator is expressed as
Wnet= Qh-Ql
=610-505
=105kJ
Also we know that the coefficient of performance is expressed as
COP= Ql/Wnet
COP= 505/105
= 4.8
Answer:
Time spent on the greenway road = 4.5 hours
Time spent on the 2 lane road = 1.5 hours
Explanation:
The distance of the trip is 360 miles and the initial speed of the car is 62 miles/hr and after the road became 2 lane highway the car slowed to 54 miles/hr.
Let us divide the trip into two
Greenway
speed = distance/time
speed = 62 mph
time = a
distance = speed × time
distance = 62a
2 lane highway
speed = distance/time
speed = 54 mph
time = b
distance = speed × time
distance = 54b
Total distance
62a + 54b = 360......................(i)
Total time
a + b = 6..............................(ii)
a = 6-b
insert a in equation (i)
62(6-b) + 54b = 360
372 - 62b + 54b = 360
-8b = 360-372
-8b = - 12
b = 12/8
b = 1.5
from equation (ii)
a + 1.5 = 6
a = 6 - 1.5
a = 4.5
<u>Answer:</u> Below 12m of depth, the submarine has to submerge so that it would not be swayed by surface waves
<u>Explanation:</u>
To avoid the surface waves, a submarine has to submerge below the wave base. It is the position below which the motion of the waves is negligible.
This wave base is equal to half of the wavelength. The equation becomes:
Wave base = 
We are given:
Wavelength = 24 m
Putting values in above equation, we get:
Wave base = 
Hence, below 12m of depth, the submarine has to submerge so that it would not be swayed by surface waves
Using the combined gas law of P1V1=P2V2 and plug it in you get (4)V1 for you don't have initial volume = (0.2)(500) --> 4V1=100, divide by the coefficient on both sides and you get V1=25