Please ignore my comment -- mass is not needed, here is how to solve it. pls do the math
at bottom box has only kinetic energy
ke = (1/2)mv^2
v = initial velocity
moving up until rest work done = Fs
F = kinetic fiction force = uN = umg x cos(a)
s = distance travel = h/sin(a)
h = height at top
a = slope angle
u = kinetic fiction
work = Fs = umgh x cot(a)
ke = work (use all ke to do work)
(1/2)mv^2 = umgh x cot(a)
u = (1/2)v^2 x tan (a) / gh
Usually nice weather , i dont know the answer to the second part
Hello!
Recall the equation for gravitational force:

Fg = Force of gravity (N)
G = Gravitational constant
m1, m2 = masses of objects (kg)
r = distance between the objects' center of masses (m)
There is a DIRECT relationship between mass and gravitational force.
We are given:

If we were to double one mass and triple another, according to the equation:

Thus:

The answer is the letter "C" ( I have honors science I am good at this type of stuff )
Hope I helped :) ( ask me for help when u need it :)
Answer:
1.38 x 10^-18 J
Explanation:
q = - 1.6 x 10^-19 C
d = 5 x 10^-10 m
the potential energy of the system gives the value of work done
The formula for the potential energy is given by

So, the total potential energy of teh system is

As all the charges are same and the distance between the two charges is same so the total potential energy becomes

K = 9 x 10^9 Nm^2/C^2
By substituting the values

U = 1.38 x 10^-18 J