Answer:
The number above the symbol is the atomic mass (or atomic weight). This is the total number of protons and neutrons in an atom. The number below the symbol is the atomic number and this reflects the number of protons in the nucleus of each element's atom. Every element has a unique atomic number.
Explanation:
Answer:
μ = tanθ = tan30 = 0.58
Explanation:
μ = force parallel/force perpendicular = mgsinθ/mgcosθ = tanθ
Answer:
the amount of energy needed is 1.8 x 10¹⁷ J.
Explanation:
Given;
mass of the object, m₀ = 1 kg
velocity of the object, v = 0.866 c
By physics convection, c is the speed of light = 3 x 10⁸ m/s
The energy needed is calculated as follows;
E = Mc²
As the object approaches the speed of light, the change in the mass of the object is given by Einstein's relativity formula;

The energy required is calculated as;
E = 2 x (3 x 10⁸)²
E = 1.8 x 10¹⁷ J
Therefore, the amount of energy needed is 1.8 x 10¹⁷ J.
If you are cold and you rub your hands together then that friction can create warmth. Useful
If you're sliding down a staircase railing and your hands are on the raiking then the friction may burn your hands a little. Not useful<span />