The concept required to perform this exercise is given by the coulomb law.
The force expressed according to this law is given by

Where,

q = charges of the objects
r= distance/radius
Our values are previously given, so

Replacing,



The force acting on the block are given by,




Therefore the box is accelerated upward.
For small deflections, T = 2*pi*sqrt(L / g) where T is period, L is length and g is gravity.
Setting the equations to the same period, 2*pi*sqrt(3.85 / g) = 2*pi*(L / (1/6 * g))
The equation reduces to 3.85 m = 6 * L so L = 0.642 m
chrsclrk · 7 years ago
Solar energy is the most abundant energy resource on earth.
Explanation:
Not being able to see the picture attached and supposing the ground level is considered to be the water level so to be able to find out the velocity you need to score into the hoop you need to use the combined force ( resulting force) to throw the ball at 6.50 m distance, 1 m below to where you are standing