Answer: v = 
Explanation: q = magnitude of electronic charge = 
mass of an electronic charge =
V= potential difference = 4V
v = velocity of electron
by using the work- energy theorem which states that the kinetic energy of the the electron must equal the work done use in accelerating the electron.
kinetic energy =
, potential energy = qV
hence, 

C. The range of a projectile increases with an increase in the angle of launch.
Answer:
130 km at 35.38 degrees north of east
Explanation:
Suppose the HQ is at the origin (x = 0, y = 0)
So the coordinates of the helicopter after the 1st flight is


After the 2nd flight its coordinate would be:


So in order to fly back to its HQ it must fly a distance and direction of
north of east
Here, you can calculate it's potential energy with respect to ground.
We know, U = mgh
Here, m = 75 Kg
g = 9.8 m/s² [ constant value for earth system ]
h = 300 m
Substitute their values into the expression:
U = 75 × 9.8 × 300
U = 220500 J
In short, Your Final Answer would be 220,500 J
Hope this helps!