(a) 0.249 (24.9 %)
The maximum efficiency of a heat engine is given by

where
Tc is the low-temperature reservoir
Th is the high-temperature reservoir
For the engine in this problem,


Therefore the maximum efficiency is

(b-c) 0.221 (22.1 %)
The second steam engine operates using the exhaust of the first. So we have:
is the high-temperature reservoir
is the low-temperature reservoir
If we apply again the formula of the efficiency

The maximum efficiency of the second engine is

Answer:
The coefficient of rolling friction will be "0.011".
Explanation:
The given values are:
Initial speed,

then,


Distance,
s = 18.2 m
The acceleration of a bicycle will be:
⇒ 
On substituting the given values, we get
⇒ 
⇒ 
⇒ 
⇒ 
As we know,
⇒ 
and,
⇒ 
⇒ 
On substituting the values, we get
⇒ 
⇒ 
Answer:
F = 75[J]
Explanation:
We know that work is defined as the product of force by distance.
In this way we have two forces, the weight of the block down, and the force that bring about the block to rise.

where:
W = work = 50 [J]
d = distance = 2 [m]
Fweight = 50 [N]
Fupward [N]
Now replacing:
![50=-(50*2)+(F_{upward}*2)\\50+100=F_{upward}*2\\F_{upward}=150/2\\F_{upward}=75[J]](https://tex.z-dn.net/?f=50%3D-%2850%2A2%29%2B%28F_%7Bupward%7D%2A2%29%5C%5C50%2B100%3DF_%7Bupward%7D%2A2%5C%5CF_%7Bupward%7D%3D150%2F2%5C%5CF_%7Bupward%7D%3D75%5BJ%5D)
Answer:
<h2>
650W/m²</h2>
Explanation:
Intensity of the sunlight is expressed as I = Power/cross sectional area. It is measured in W/m²
Given parameters
Power rating = 6.50Watts
Cross sectional area = 100cm²
Before we calculate the intensity, we need to convert the area to m² first.
100cm² = 10cm * 10cm
SInce 100cm = 1m
10cm = (10/100)m
10cm = 0.1m
100cm² = 0.1m * 0.1m = 0.01m²
Area (in m²) = 0.01m²
Required
Intensity of the sunlight I
I = P/A
I = 6.5/0.01
I = 650W/m²
Hence, the intensity of the sunlight in W/m² is 650W/m²