Science test help?

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A student applies a force to the stone block as shown. what is the best picture that represents the reaction force provided by the block to the student?
Anyone please

>>134909
When you push on a wall the wall pushes back on your hand with the exact same amount of force. This is what it means by reaction force. D

>>134913
Thanks anon.
You still want to help?

>>134903
B
>>134906
3
>>134909
D

THANKS SO MUCH ANON

>>134921
I disagree
Pulley acts as a lever so isn't 1 also a mechanical advantage ? Explain this shuit

>>134923
The 1st and 3rd ones are the correct answers, so yes

>>134907
>>134923

2 & 3 give mechanical advantage, which is defined by reducing the force required to apply work. (Note also that 3 is just a combination of 1 and 2.)

>>134923
>>134935
>>135256
Work is always the same, because of conservation of energy.

If you increase the distance the work is applied over, the force decreases, again because of conservation of energy.

_Increasing the distance and reducing the force is called "mechanical advantage"._

Pulley 1, you pull the string down the same distance as you'd pull the weight up, so as the distance is the same, the force is the same, and there's no mechanical advantage.

Pulleys 2 and 3, you pull twice as much string as the distance the weight travels, so the force is half, and there is mechanical advantage.

Finally, you have to be 18 to post here.

>>134903
>>134904

Are you fucking retarded?