It corrodes the copper by oxydation
A projectile motion is characterized by motion moving in a direction of an arc. It is acted upon by two component vectors: the horizontal and vertical. These two vectors are independent of each other when it comes to time of flight. The horizontal direction travels at constant speed, while the vertical direction travels at constant acceleration due to gravity, The time for an object to reach the ground would be equal, whether dropped from the sampe point or thrown in a projectile motion. Of course, this is assuming ideality wherein there is no air resistance.
So, the hang up time, or the time the object stayed on air is calculated using this equation:
a = Δv/t
Δv is the change in velocity which is the initial velocity when it was dropped to when it reaches zero velocity when it hits the ground.
9.81 m/s² = |(0 - 7.3)|/t
t = 0.744 seconds
The formula is=1/2(m x v^2)
so = 1/2*(0.05)*(310)^2
ans is =2402.5 joules
Each 
ion contains three extra protons. Hence, the extra charge on each = 
C
Total charge = 0.035 pC
Total charge (Q) = 
C
Let the number of ions be n.
According to question:
n = 72917
Hence, the total number of ions needed to be transferred is 72917
<span>1 cal = 4,185 J
1 kcal = 1*10^3 cal
or
=1000 cal</span>
