Answer:

Explanation:
The density changes means that the length in the direction of the motion is changed.
Therefore,

Given :
Side, b = h = 0.13 m
Mass, m = 3.3 kg
Density = 8100 
So,


l = 0.024 m
Then for relativistic length contraction,







Therefore, the speed of the observer relative to the cube is 0.9833 c (in the units of c).
Answer:
The equivalent capacitance will be
Explanation:
We have given two capacitance 
They are connected in parallel
So equivalent capacitance 
This equivalent capacitance is now connected in series with 
In series combination of capacitors the equivalent capacitance is given by 

So the equivalent capacitance will be
Ferromagnetic, paramagnetic, and diamagnetic
Answer:

Explanation:
The situation can be described by the Principle of Energy Conservation and the Work-Energy Theorem:

The work done on the ball due to drag is:


![W_{drag} = (0.599\,kg)\cdot (9.807\,\frac{m}{s^{2}} )\cdot (2.18\,m-3.10\,m)+\frac{1}{2}\cdot (0.599\,kg)\cdot [(7.05\,\frac{m}{s} )^{2}-(4.19\,\frac{m}{s} )^{2}]](https://tex.z-dn.net/?f=W_%7Bdrag%7D%20%3D%20%280.599%5C%2Ckg%29%5Ccdot%20%289.807%5C%2C%5Cfrac%7Bm%7D%7Bs%5E%7B2%7D%7D%20%29%5Ccdot%20%282.18%5C%2Cm-3.10%5C%2Cm%29%2B%5Cfrac%7B1%7D%7B2%7D%5Ccdot%20%280.599%5C%2Ckg%29%5Ccdot%20%5B%287.05%5C%2C%5Cfrac%7Bm%7D%7Bs%7D%20%29%5E%7B2%7D-%284.19%5C%2C%5Cfrac%7Bm%7D%7Bs%7D%20%29%5E%7B2%7D%5D)

Answer:
Metals are the good conductors of heat while plastic is a non metal and is not good in conductivity.
Explanation:
From the molecular point of view we usually define conductivity in terms of free electrons which are in abundance in metal and electrons do transfer heat. So when you touch a piece of metal these free electron of metal take that heat from your hand and transfer to the cooler part. "Flow of heat from hotter to colder part". That is the reason it feels colder upon touching the piece of metal. However Plastics do not have this characteristic of conduction of heat.