Can y’all help with number 2, 4,5,6?

2)Ek = 686.7[J]; 4)  see the explanation part; 5) B) Remained motionless; 6) P = 339 [watt]

Explanation:

2)

Using, the principle of energy conservation we can find the kinetic energy of the rock. We must bear in mind that the potential energy as the rock falls is becoming kinetic energy.

Now replacing the values:

4)

5)

B) Remained motionless

The reason is that work is defined as the product of force by distance, when there is no work for this case, it is because there is no movement of the object due to force.

6)

We recall that work is defined as the product of force by distance

W = F * d

W = 113 * 27

W = 3051[J]

And power is defined as the amount of work performed over a time interval.

Power = W/t

Power = 3051/9

Power = 339 [watt]

0.19 m/s and 0.45 m/s

the box does not move because you need to use a force greater than 300 n. you are only using 50 n. it needs to at least be 301 n for the box to move because then it is an unbalanced force and it will move the way that the greater force is pushing it. if you use only 300 n it will be a balanced force and will not move because the force you are exerting on the   box is the same as its force.

hope this !

im sorry if i went too in depth, i am going to include a link to a video on khan academy that will explain this.   hope that you like the video and that it explains more in detail to you.

that is the link.