Answer:

Explanation:
We know,
..............(1)
where,
η = Efficiency of the engine
T₁ = Initial Temperature
T₂ = Final Temperature
Q₁ = Heat available initially
Q₂ = Heat after reaching the temperature T₂
Given:
η =0.280
T₁ = 3.50×10² °C = 350°C = 350+273 = 623K
Q₁ = 3.78 × 10³ J
Substituting the values in the equation (1) we get

or

or

⇒ 
Now,
The entropy change (
) is given as:

or

substituting the values in the above equation we get


The work done to accelerate the acrobat is given by

where F is the force applied and d the distance of application of the force.
If the barrel is 3.05 m long, then d=3.05 m. Therefore we can find the force:
Answer:
<h3>Vab=Va-Vb</h3><h3>Vab=Vb-Va</h3><h3>
Explanation:</h3>
Vab is velocity of a relative to b
Vba is velocity of b relative to a
Answer:
Image is between F and 2F. And the exact location is:
q = 10.84 cm
Explanation:
The convex lens form different kinds of images with different sizes and locations, for the different positions of an object. In this case, the object is placed 30.5 cm from the convex lens with a focal length of 8 cm. This means that it is the case of the object placed beyond 2F. In this case, the image formed has the following characteristics:
1. Image is real.
2. Image is inverted
3. Image is diminished
<u>4. Image is located between F and 2F</u>
For exact location we use the thin lens formula:

where,
f = focal length = 8 cm
p = object distance = 30.5 cm
q = image distance = ?
Therefore,

<u>q = 10.84 cm</u>