The first rule of vectors is that the horizontal and vertical components are separate. Disregarding air resistance, the only thing we have to worry about is gravity.
The appropriate suvat to use for the vertical component is v = u +at
I will take a to be -9.81, you may have to change it to be 10 if your qualification likes g to be 10.
v = 30 + (-9.81x2)
v = 30 - 19.62
=10.38m/s
Therefore we know that after 2.0 s the vertical component will be 10.38ms^-1, ie 10m/s as the answers given are all to 2sf.
The horizontal component is completely separate to the vertical component and since there is no air resistance, it will remain constant throughout the projectiles trajectory. Therefore it will remain at 40ms^-1.
Combining this together we get:
(1) vx=40m/s and vy=10m/s
6489 for the founding product
Explanation:
Use Pythagorean theorem:
r² = x² + y²
r² = (-6.46 m)² + (-3.78 m)²
r = 7.48 m
Explanation:
Given that,
Charge 1, 
Charge 2, 
Distance between charges, r = 0.0209 m
1. The electric force is given by :
F = -492.95 N
2. Distance between two identical charges, 
Electric force is given by :
Hence, this is the required solution.
