A magnetic field is produced by moving electric charges so B
Answer:
Velocity of a proton,
Explanation:
It is given that,
Potential difference, 
Let v is the velocity of a proton that has been accelerated by a potential difference of 15 kV.
Using the conservation of energy as :

q is the charge of proton
m is the mass of proton




or

So, the velocity of a proton is
. Hence, this is the required solution.
Answer:
2 /s north
Explanation:
Given that,
Velocity due North is 8 m/s and due south is 6 m/s
We need to find the magnitude and the direction of the resulting velocity.
Let North is positive and South is negative. When two velocities are in opposite direction, they adds up. So,

It is positive. So, it is in North direction.
Explanation:
700N right
to get the net force
you gotta let one direction be the negative ( the smaller force)
so the total force towards the left is 100N ( 60 + 40= 100)
which is smaller than the right force which is 800 N so you let 100 N be negative
so without even calculating , you can know that it will be moving towards the right because right force > left force
your add both forces ( remember 100 N is negative)
so 800N + ( - 100N)
= 700N
towards the right
hope this helps
this is just one method that helped me understand
please mark it brainliest