<h3><u>Answer</u> :</h3>
First of all, See the attachment for better understanding
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❂ <u>Weight of block A</u> :
➝ mg sin30° = 18
➝ W (1/2) = 18
➝ W = 18×2
➝ <u>W = 36N </u>
❂ <u>Weight of block B</u> :
➝ N sin30° = 18
➝ (Mg cos30°) sin30° = 18
➝ W' (√3/2)(1/2) = 18
➝ W' (√3/4) = 18
➝ W' = 72/√3
➝ <u>W' = 41.61N</u>
There are some missing data in the problem. The full text is the following:
"<span>A </span>real<span> (</span>non-Carnot<span>) </span>heat engine<span>, </span>operating between heat reservoirs<span> at </span>temperatures<span> of 710 K and 270 K </span>performs 4.1 kJ<span> of </span>net work<span>, and </span>rejects<span> 9.7 </span>kJ<span> of </span>heat<span>, in a </span>single cycle<span>. The </span>thermal efficiency<span> of a </span>Carnot heat<span> engine, operating between the same </span>heat<span> reservoirs, in percent, is closest to.."
Solution:
The efficiency of a Carnot cycle working between cold temperature </span>

and hot temperature

is given by

and it represents the maximum efficiency that can be reached by a machine operating between these temperatures. If we use the temperatures of the problem,

and

, the efficiency is

Therefore, the correct answer is D) 62 %.
its c electromagnetic waves must have a medium in which to travel, but sound waves can travel anywhere.
Answer:
The electric field due to the right ring at a location midway between the two rings is 
Explanation:
Given that,
Radius of first ring = 5 cm
Radius of second ring = 20 cm
Charge on the left of the ring = +30 nC
Charge on the right of the ring = -30 nC
We need to calculate the electric field due to the right ring at a location midway between the two rings
Using formula of electric field
Put the value into the formula


Hence, The electric field due to the right ring at a location midway between the two rings is 
The mass of the skydiver is 122.2 kg
Explanation:
We can solve the problem by using the concept of weight.
The weight of a body is the force of gravity acting on the body; near the Earth's surface, its magnitude is given by

where
m is the mass of the body
is the acceleration of gravity
In this problem, we know the weight of the skydiver:
W = 1198 N
So we can re-arrange the equation to find its mass:

Learn more about weight here:
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