As stated in the statement, we will apply energy conservation to solve this problem.
From this concept we know that the kinetic energy gained is equivalent to the potential energy lost and vice versa. Mathematically said equilibrium can be expressed as


Where,
m = mass
= initial and final velocity
g = Gravity
h = height
As the mass is tHe same and the final height is zero we have that the expression is now:






Answer:
V = 192 kV
Explanation:
Given that,
Charge, 
Distance, r = 0.3 m
We need to find the electric potential at a distance of 0.3 m from a point charge. The formula for electric potential is given by :

So, the required electric potential is 192 kV.
Explanation:
d= 80km = 8000m
t = 45 min = 45/60 h
= 0.75 h
V= ?
we know that,
V = d /t
or,V= 80 km / 0.75 h
- or, V= 106.67 km/hr
or,V= 106.67×1000m / 3600 s
2. or, V= 29.63 m/s
1 hour for the train to travel 17,000 feet
Let
denote the position vector of the ball hit by player A. Then this vector has components

where
is the magnitude of the acceleration due to gravity. Use the vertical component
to find the time at which ball A reaches the ground:

The horizontal position of the ball after 0.49 seconds is

So player B wants to apply a velocity such that the ball travels a distance of about 12 meters from where it is hit. The position vector
of the ball hit by player B has

Again, we solve for the time it takes the ball to reach the ground:

After this time, we expect a horizontal displacement of 12 meters, so that
satisfies

