Home » Posts tagged 'conservation'

# Tag Archives: conservation

## Will the mass of earth reduce due to extraction of fossil fuels?

Is it possible that the earth mass would be reducing due to extraction of fossil fuels?
If so, would it affect to its movement and position in solar system?

There won’t be any considerable loss of mass. The amount of mass irrecoverably lost is negligibly small on its conversion to energy .

It’s just like arguing that constructing more and more buildings will increase the mass of earth. !! No such thing happens. There is only a rearrangement of matter and inter conversion of mass and energy.

## Where is the light energy going?

where is the sun’s light enery going once the sun has set?

or

where is the light going when we switch off the torch facing an object. if light gets reflected how long it will do so. and if it gets absorbed, then will it add to the potential energy of the object that is facing the torch?

or

Is there any cycle (like hydrocycle)to prove that energy can neither be created nor be destroyed?

## Bouncing ball and energy dissipation problem

A player throws a ball of mass 0.6 kg into the air, to a height of 4.0 m above the ground. The ball then falls to the ground. During the impact, 22% of the ball’s energy is lost. Calculate the height to which the ball rises after the bounce. Your assistance will be appreciated..

Mustafa posted

m= 0.6 kg

h = 4.0 m

Energy = mgh

During impact 22% energy is lost. Therefore, energy remaining = 88%

Therefore the energy with which the ball rebounds = 24 x 88/100 J

This is equal to the potential energy at the highest point after bouncing

If the new height is h’

mg h’ = 88% mgh

h’ = 0.88 x h = 0.88 x 4.0 =3.52 m

## Electron behaviour

Why an electron in level N when it gain energy it go to a higher energy level , why not going to a lower energy level , considering that word “higher” and “lower” refers to no of energy level but the energy of the energy level decrease as we go away from nucleus so an excited electron that gain an additional energy transfer to a higher energy level in no but lower in energy so why the electron doesn’t from its level to a lower energy level in no but higher in energy so the new energy level can bear the energy of the excited electron ?
The question is not very clear. If you can explain it further, it will be better to discuss here.

Regards,

## Physics of Diving

When a high diver in a swimming event springs from the board and “tucks in”, a rapid spin result. Why is this?

Answer: This is the consequence of conservation of angular momentum.

The angular momentum of a body is the product of Moment of inertia (A measure of rotational inertia and it depends on the mass as well as distribution of mass about the axis of rotation. Farther the masses, greater will be the rotational inertia) and the angular velocity (The speed of rotation)

The angular momentum of a body remains unchanged in the absence of any external torque.

When the diver dives, he is giving his body a turning and takes off with his limbs stretched. In the stretched position, the moment of inertia is more. When he “tucks in”, the moment of inertia decreases. But since this happens without any external torque, it would result in an increase in angular velocity so as to keep the angular momentum constant.

## Principles of Physics in Chemistry

“is there any priciples of phy involed in chemical reactions ?”
Physics and Chemistry are the two main branches of Physical Science, the branch of science which discusses nature and its properties and the various phenomena associated with it.
Some of the Principles to mention are
The Principles of conservation,
Thermal expansion
How to hold a test tube, pipette, Burette etc?
(Visitors are requested to add more)

## Electromagnetic induction in outer space and energy conservation

“lets pretend we are in space. and there  I have a permanent magnet rotor that and around it are copper windings. They do not touch and everything is floating with minimum friction (because we are in space)
imagine a generator with no brushes or bearings….

now my question is :
if i spin the rotor, and electrons start flowing on the copper(electricity)
would there be a negative force on the rotor to make it stop faster ?

Thank you

(Posted by )

Waiting for public response

### Hits so far @ AskPhysics

• 2,239,550 hits