Work = (force) x (distance)
Each time she lifts the weight, she does
(550 N) x (0.5 m) = 275 joules of work against gravity.
Each time she lets the bar down gently, gravity does
(550 N) x (0.5 m) = 275 joules of work against her muscles.
If the human physical muscular system were 100% efficient, and capable
of absorbing work as well as spending it, then the bodybuilder would do
exactly zero work in the process of 1-up followed by 1-down.
The answer would be B. Magnetic fields are invisible they cannot be directly observed
Answer:
The radius is 
Explanation:
From the question we are told that
The distance beneath the liquid is 
The refractive index of the liquid is 
Now the critical value is mathematically represented as
![\theta = sin ^{-1} [\frac{1}{n_i} ]](https://tex.z-dn.net/?f=%5Ctheta%20%3D%20%20sin%20%5E%7B-1%7D%20%5B%5Cfrac%7B1%7D%7Bn_i%7D%20%5D)
substituting values
![\theta = sin ^{-1} [\frac{1}{131} ]](https://tex.z-dn.net/?f=%5Ctheta%20%3D%20%20sin%20%5E%7B-1%7D%20%5B%5Cfrac%7B1%7D%7B131%7D%20%5D)

Using SOHCAHTOA rule we have that

=> 
substituting values


The force applied to lift the crate is 171 N
Explanation:
The lever works on the principle of equilibrium of moments, so we can write:

where
is the force in input
is the arm of the input force
is the output force
is the arm of the output force
For the lever in this problem, we have:


(force applied)
Solving the equation for
, we find the force applied to lift the crate:

Learn more about levers:
brainly.com/question/5352966
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