Answer:
A)
B)
Explanation:
<u>Given:</u>
Length of the room 
Width of the room 
A) Let A be the area of the room

B)We will calculate uncertainty in each dimension
%uncertainty in length
%uncertainty in width =
The uncertainty in area will be sum of uncertainty in length and width
%uncertainty in Area= %uncertainty in length + %uncertainty in width
%uncertainty in Area
%uncertainty in Area=0.0106
Uncertainty in Area
There Area is
More force needs to be applied
The efficiency of the engine at the given useful energy and input energy is 28%.
The given parameters:
- <em>Input energy of the engine, = 125 J</em>
- <em>Useful energy of the engine, 35 J</em>
The efficiency of the engine is defined as the ratio of the output energy (useful energy) to the input energy and it is calculated as follows;

Thus, the efficiency of the engine at the given useful energy and input energy is 28%.
Learn more about efficiency of engine here: brainly.com/question/6751595