Given conditions:
height of object = 7.5cmdistance of object from mirror = 14 cmfocus length = -7 cmimage distance = ?
Using mirror formula:
1/(focus length) = 1/(object distance) + 1/(image distance)
or, -1/7 = 1/14 + 1/(image distance)
or, image distance = -4.66cm (the image formed is a virtual image)
Also, magnification of image is:
image height /height of object = - image distance /object distance
or, image height = - image distance / object distance * height of object
or, image height = -(-4.66) / 14 * 7.5 = 2.49 = 3(nearest whole number)
Answer:
part (a) 
Part (b) 
Explanation:
Given,
- Mass of the larger disk =

- Mass of the smaller disk =

- Radius of the larger disk =

- Radius of the smaller disk =

- Mass of the block = M = 1.60 kg
Both the disks are welded together, therefore total moment of inertia of the both disks are the summation of the individual moment of inertia of the disks.

part (a)
Given that a block of mass m which is hanging with the smaller disk,
Let 'T' be 'a' be the tension in the string and acceleration of the block.
From the free body diagram of the smaller block,

From the pulley,

From the equation (1) and (2),

part (b)
Above expression for the acceleration of the block is only depended on the radius of the pulley.
Radius of the larger pulley = 
Let
be the acceleration of the block while connecting to the larger pulley.
Answer:
30,000 units, because total energy remains unchanged
A device that uses electromagnetic induction to transfer electrical energy from one circuit to another is a transformer.
<h3>Which device uses electromagnetic induction to transfer electrical energy from one circuit to another?</h3>
- A transformer is an electrical device that transfers energy from one electric circuit to another using the electromagnetic induction principle.
- It is intended to change the AC voltage between the circuits while keeping the current's frequency constant.
- A transformer work on the principle of electromagnetic induction in which flux is linked from primary to secondary.
- Transformers accomplish this without establishing a conductive link between the two circuits. This is made feasible by using Faraday's Law of Induction, which explains how an electric circuit will interact with a magnetic field to produce an electromotive force (EMF).
To learn more about transformers refer:
brainly.com/question/25886292
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