Answer:
Explanation:
The apple also exerts an equal and opposite force on the earth but earth does not move because the mass of apple is very small,due to which the gravitational force produces a large acceleration in it (a=F/m) and we can see the apple falling towards the earth but the mass of earth is very large,the same gravitational .
Answer:
For number 4: A vector pointing to the right with a magnitude of 2.0
Explanation:
Very simple- just subtract 6-2
I am not sure how to do #2- sorry!
Answer:

The Magnitude of electric field is in the upward direction as shown directly towards the charge
.
Explanation:
Given:
- side of a square,

- charge on one corner of the square,

- charge on the remaining 3 corners of the square,

<u>Distance of the center from each corners</u>


∴Distance of center from corners, 
Now, electric field due to charges is given as:

<u>For charge
we have the field lines emerging out of the charge since it is positively charged:</u>

<u>Force by each of the charges at the remaining corners:</u>

<u> Now, net electric field in the vertical direction:</u>


<u>Now, net electric field in the horizontal direction:</u>


So the Magnitude of electric field is in the upward direction as shown directly towards the charge
.