The density of an object can be calculated using the formula Density = Mass/Volume.
Experimental Density:
Density = 153.8g / 20.00 cm^3
Density = 7.69g/cm^3
Percent error equation:
% Error = | Theoretical Value - Experimental Value|/Theoretical Value * 100
% Error = | 7.87g/cm^3 - 7.69g/cm^3|/7.87g/cm^3 * 100
% Error = 2.29%
Therefore a is the correct answer.
Answer:
a) m=20000Kg
b) v=0.214m/s
Explanation:
We will separate the problem in 3 parts, part A when there were no coals on the car, part B when there is 1 coal on the car and part C when there are 2 coals on the car. Inertia is the mass in this case.
For each part, and since the coals are thrown vertically, the horizontal linear momentum p=mv must be conserved, that is, 
, were each velocity refers to the one of the car (with the eventual coals on it) for each part, and each mass the mass of the car (with the eventual coals on it) also for each part. We will write the mass of the hopper car as 
, and the mass of the first and second coals as 
and 
respectively
We start with the transition between parts A and B, so we have:
Which means
And since we want the mass of the first coal thrown () we do:
Substituting values we obtain
For the transition between parts B and C, we can write:
Which means
Since we want the new final speed of the car (
) we do:
Substituting values we obtain
Quantitative because it tells you how many wheels
If only internal forces are doing work (no work done by external forces), then there is no change in the total amount of mechanical energy. The total mechanical energy is said to be conserved. ... In these situations, the sum of the kinetic and potential energy is everywhere the same.
Explanation:
This difference is because of the difference in arrangement of carbon atoms both graphite and Diamond.
Carbon atoms in graphite are arranged in layered form in an infinite array of layers. These layers are held together by a weaker force of attraction called vander waal's force of attraction such that layer's can slip over one another. Whereas in diamond carbon atoms are arranged tetrahedrally. Each carbon atom is attached to four carbon atoms with a bond angle of 109.5°. It is strong rigid three dimensional structure that results in infinite array atoms. This accounts for hardness of the diamond.
