Answer:
1 and 3
Explanation:
because they are going up from 0
1) In the reference frame of one electron: 0.38c
To find the relative velocity of one electron with respect to the other, we must use the following formula:

where
u is the velocity of one electron
v is the velocity of the second electron
c is the speed of light
In this problem:
u = 0.2c
v = -0.2c (since the second electron is moving towards the first one, so in the opposite direction)
Substituting, we find:

2) In the reference frame of the laboratory: -0.2c and +0.2c
In this case, there is no calculation to be done. In fact, we are already given the speed of the two electrons; we are also told that they travel in opposite direction, so their velocities are
+0.2c
-0.2c
Answer:
The horizontal velocity is 
Explanation:
From the question we are told that
The mass of the pumpkin is 
The distance of the the car from the building's base is 
The height of the roof is 
The height is mathematically represented as

Where g is the acceleration due to gravity which has a value of 
substituting values

making the time taken the subject of the formula


The speed at which the pumpkin move horizontally can be represented mathematically as

substituting values


Answer:
No, it is not attracted.
Explanation:
If any sphere is electrically neutral it is not attracted. The materials which are attracted by magnet are called magnetic material whereas which are not attracted are called non magnetic material. Sphere made up of non magnetic materials such as glass, wood, paper will not attracted weather is kept near north pole or near south pole.