A) From rest and before performing the described exercise, the entire weight of the desk is supported by the floor. This support force (normal force) exerted by the floor will be equivalent to the force equivalent to the weight of the desk. From the moment the desk starts to be lifted, said support force will decrease and the weight of the desk supported by the floor will be less.
B) As the desk is lifted, the support force of the two guests will increase, this occurs because the force is transferred to the support of both, but the support force of the floor on the two people will increase.
Answer:
4N downward
Explanation:
the 16N left and right cancel each other out, so you are left with the 4N downward.
Modelling the structure of the atom is important because modeling replaces the real system with something similar but easier to examine. Option B
<h3>What is modeling?</h3>
A model is a representation of reality. We know that a model could help us to recreate reality in a manner that we could be able to relate fully with it. A model could be used also a means of explanation.
The atomic models that we have usually help us to understand more abut the atom. Therefore, modelling the structure of the atom is important because modeling replaces the real system with something similar but easier to examine. Option B
Learn more about modelling the atom:brainly.com/question/1596638
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Answer:

Explanation:
As we know that moment of force is given as

now we have


now from above formula we have

here we know that

so we have


Answer:
Distance = 3.69 × 10^9 m
The distance from the probe to Earth is 3.69 × 10^9 m
Explanation:
Distance from the probe to the Earth can be derived using the simple motion formula;
Distance = speed × time .....1
Since a radio signal uses an electromagnetic wave to transfer signal, it has the same speed as the speed of light.
Speed of radio signal = speed of light = 3.0 × 10^8 m/s
time taken to reach the earth = 12.3 seconds
Substituting the values of speed and time into equation 1;
Distance = 3.0 × 10^8 m/s × 12.3 s
Distance = 36.9 × 10^8 m
Distance = 3.69 × 10^9 m
Note: all electromagnetic radiation have the same speed which is equal to 3.0 × 10^8 m/s