Answer:
The minimum work per unit heat transfer will be 0.15.
Explanation:
We know the for a heat pump the coefficient of performance (
) is given by
where, 
is the magnitude of heat transfer between cyclic device and high-temperature medium at temperature 
and 
is the required input and is given by 
, 
being magnitude of heat transfer between cyclic device and low-temperature 
. Therefore, from above equation we can write,
Given, 
and 
. So, the minimum work per unit heat transfer is given by
Answer:
1.) 4m
2.) 37 m
3.) 62m
4.) 2.5 s
Explanation:
1.) Given that the
Thinking distance = 1m
Breaking distance = 3m
Stopping distance = breaking distance + thinking distance
Stopping distance = 1 + 3 = 4m
2.) Given that the
Stopping distance = 52 m
Thinking distance = 15m
Breaking distance = 52 - 15 = 37m
3.) The stopping distance = 76m
Thinking distance = 14m
Breaking distance = 76 - 14 = 62m
It take the brakes 62m to slow the car down to a stop.
4.) Given that a lorry travels 28m when stopping from a speed of 4m/s. If its braking distance was 18m, what was the driver’s reaction time?
Thinking = stopping distance - braking distance
Thinking distance = 28 - 18 = 10m
Speed = distance/time
4 = 10/reaction time
Reaction time = 10/4
Reaction time = 2.5 s
5.) Question incomplete
Answer:
wavelength = 0.968 m
frequency = 39.02 Hz
Explanation:
given data
mass = 0.0127 kg
force = 9.33 N
length = 1.93 m
to find out
wavelength and Frequency
solution
we know here linear density that is
linear density = 
.........1
linear density = 
linear density = 6.5803 × 
kg/m
so
wavelength will be here
wavelength = 
..............2
here n = 4 for forth harmonic
wavelength = 
wavelength = 0.968 m
and
frequency will be for 4th normal mode of vibration is
frequency = 
..........3
frequency = 
frequency = 1.036269 × 37.654594
frequency = 39.02 Hz
Answer:
The speed change during the 45-minute trip is 20[mph]
Explanation:
When we see the speed at the 45 minutes this is 20 [mph] and at the 0 minutes the speed is 0 [mph].
Therefore the change is (20 - 0) = 20 [mph]
In the attached image we can see the different figures. In fig 1 we can see the bicycle's speed after 10 minutes when the speed becames constant.
In the fig. 2 we can find the graph when the biker stopped at 30 minutes and took a 15-minute break.
Figures 3 and 4, show the differences when a horizontal line is traced on a position vs time graph, and when the horizontal line is traced in a speed vs time graph.
For fig 3 we can conclude that the body is not moving therefore there is no velocity or acceleration. And for the fig 4, we can realize that the area under the horizontal line represents a displacement during the respective interval of time.
