Nuclear energy that what I think it is
Answer:
READ THIS FIRST!!!
I am not going to right the parragraph (it says to use your own words, they could trace it back to me if you use my words, and you would get it trouble).
But I will tell you the forces acting on the pencil:
Gravity (pulls on the pencil)
Your hand (pushing it up canceling out gravity)
And the electromagnetic force (holding the thing together)
Hope it helped,
Have a good day
Answer:

Explanation:
m = Mass of roller coaster = 2000 kg
r = Radius of loop = 24 m
v = Velocity of roller coaster = 18 m/s
g = Acceleration due to gravity = 
Normal force at the point will be

The force exerted on the track is
.
Given parameters:
Mass on earth = 50kg
Unknown:
Mass on planet Xenon = ?
Weight on planet Xenon = ?
Mass is the amount of matter contained in a particular substance.
Weight is the force on a body and it is derived from the product of mass and acceleration due to gravity.
Weight = mass x acceleration due to gravity
Planet Xenon has half the gravitational force of Earth.
This translated gives
= 4.9m/s²
Now, mass is always the same every where if the amount of matter in a substance does not change.
In this problem, mass = 50kg on planet xenon.
Weight = mass x acceleration due to gravity = 50 x 4.9 = 245N
The weight on Xenon is 245N and the mass is 50kg