Answer:

Explanation:
let the ladder is of mass "m" and standing at an angle with the ground
So here by horizontal force balance we will have

by vertical force balance we have

now by torque balance about contact point on ground we will have

so we will have

now from first equation we have


The engine efficiency is 64.73 %
<u>Explanation:</u>
Given data
To find the engine’s efficiency we have the formula,
Energy input- 4565 KJ
Energy output - 2955KJ
Efficiency= energy output/ energy input ×100%
=2955/4565
=0.6473 ×100
η =64.73 %
The engine efficiency is 64.73 %
Assuming it is on a horizontal surface:
friction = μR
R = 20g (g is gravity 9.81)
so Friction = 0.085 x 20g
Work done is force x distance
so Work done = 0.085 x 20g x 28
= 466.956 J
A the stamen :)). haha yea smert
Answer:
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