Auniform electric field (constant in magnitude and direction) exists in the region between two oppositely charged plane parallel plates. a proton is released from rest at the surface of the positively charged plate and strikes the surface of the opposite plate, 1.60 cm distant from the first, in a time interval of 2.90×10−6 s .
a) find the magnitude of the electric field. express your answer with the appropriate units.
b) find the speed of the proton when it strikes the negatively charged plate. express your answer with the appropriate units.

Part a)

Part b)

Explanation:

Part a)

Proton is released from one plate and strike at other plate in time

now we will have

now we know that

Part b)

Speed of the proton when it strike the other plate can be calculated by kinematics equations

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.

3. dark matter

empty space could also be a simple vacuum