Graphite is great lubricant because each carbon atom forms weak covalent bonds with three other carbon atoms.
Diamond and graphite both are entirely made up of carbon but both the elements are completely different because of the bonding of carbon atoms. In graphite the carbon atoms form weak covalent with the other three carbon atom due to which there is less or no force between the atoms, and makes the graphite very soft and slippery, and graphite act as lubricant.
It sounds like a special relativity question but I need more info for a total answer. But remember it's length in the lab frame is
L•sqrt(1-(v/c)^2) where L is the rest length, v is its velocity magnitude and c is the speed of light. Sqrt is the square root (I'm on a phone so I can't see the math equation editor)
A) 222 N/m
Explanation:
Hook's law gives us the relationship between force (F), displacement with respect to the original length (x) and spring's constant (k):
In this part of the problem, we have:
F = 120 N - 100 N = 20 N is the new force applied
x = 9.0 cm = 0.09 m is the displacement relative to the initial stretched position
Solving the equation for k, we find the spring constant
B) 45 cm
We can use Hook's law also for this part of the exercise:
where this time we have
F = 100 N (the original pull applied)
k = 222 N/m
Solving the equation for x, we find the original displacement:
1. the tilt of Earth's axis
2. March, April, and May
3. When an object turns around an internal axis (like the Earth turns around its axis) it is called a rotation. When an object circles an external axis (like the Earth circles the sun) it is called a revolution.
4. orbit and tilted axis and the tilt of the Earth on its axis changes the seasons.
5. The North Pole
6. The positioning of the sun
7. equinox