The image distance when a boy holds a toy soldier in front of a concave mirror, with a focal length of 0.45 m. is -0.56 m.
<h3>What is image distance?</h3>
This is the distance between the image formed and the focus when an object is placed in front of a plane mirror.
To calculate the image distance, we use the formula below.
Formula:
- 1/f = 1/u+1/v........... Equation 1
Where:
- f = Focal length of the mirror
- v = Image distance
- u = object distance
From the question,
Given:
Substitute these values into equation 1 and solve for the image distance
- 1/0.45 = 1/0.25 + 1/v
- 2.22 = 4+1/v
- 1/v = 2.22-4
- 1/v = -1.78
- v = 1/(-1.78)
- v = -0.56 m
Hence, The image distance is -0.56 m.
Learn more about image distance here: brainly.com/question/17273444
Answer:
The value is 
Explanation:
From the question we are told that
The work input is
The heat delivered is 
The value of A is A = 14
The value of B is B = 72
Generally the efficiency of the heat engine is mathematically represented as

Here
is the total out energy produce by the heat engine and this is mathematically represented as

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So

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Fusion reactions happen in stars