the gravitational force of attraction between two objects depend on their masses and the distance between them.if so,the mass of both the objects is doubled.what change is brought about in the distance between them to ensure that the force of attraction between them does not change?
- Balancing Brooms: It’s Not About the Planets (wired.com)
- Astronomers using NASA’s Hubble discover quasars acting as gravitational lenses (eurekalert.org)
The following questions were asked in MCQ section of CBSE Class 10 Board Exam (AISSE 2012)
Q1) A Student has to determine the focal length of a concave mirror by obtaining the image of a distant object on a screen . For getting best result he should focus –
a) a distant tree or an electric pole
b) a well-illuminated distant building
c) well-lit grills of nearest window
d) a burning candle placed at the distant edgeof laboratory table
Q2) A student obtained a sharp inverted image of an distant tree on the screen placd in front of concave mirror . he then removed screen and tried to look into mirror. he would now see-
a) a very blurred image on the wall opposite to the mirror
b) an erect and magnified image of the tree in the mirror
c) no image as screen has been removed
d) a highly diminished inverted image ofthe tree at the focus of the tree
- How was CBSE Science Exam for Class X? (physics.2lv.in)
- How was the CBSE Physics Exam 2012? (plustwophysics.com)
- Mark Distribution in Physics for CBSE for 2013 Board Exam (AISSCE) (physicsfans.com)
- Class 10 CBSE Science Summative Assessment II (physics.2lv.in)
- How was your AISSCE (CBSE) Chemistry Question Paper 2012? (plustwophysics.com/2lv/chemistry/)
- CBSE Class XI Chemistry Unit Test (First Term) (plustwophysics.com/2lv/chemistry/)
- Class XI CBSE Chemistry Model Paper (education2home.com)
- Distinguish Plane mirror, Concave mirror and Convex mirror without touching (plustwophysics.com)
Could u pls read my below theory of the universe [Ramkumar posted this]
and pls contact me when done with ur real frank comments…..
Assumption:Matter is Infinitely divisible…
if so we can infinitely into the micro and levels…
Matter can be divided into many levels
upon their size
this that only result of 1 level affects
the above and below levels…
the levels are consistent…
i.e the levels are complete in their sense….
this whole theory is better explained with an example.
there is the microlevel comprising of atoms something below the micro levels
comprising of what we call ‘elementary particles’ or simply fermions comprising of leptons ,quarks etc…
and there is a level above the macro level i.e
the cosmic level comprising of planets, stars etc..
what i’m saying that we cant completly explain the macro level with the micro level but using the resultant of the micro level…
like we say that since we see neutral things there are equal no: of protons and electrons making the macro object neutral….
we are only seeing the resultant o the micro level on the macro level…
we dont see protons ,electrons etc….
lly the resultant of the micro level
comes into the macro level and the resultant of the macro level comes into the cosmic level….
and vice versa ….
what i’m saying is that
we can only explain ‘things’ the micro level using the micro level only
but we can explain the micro level as a whole using the resultant of the macro level…..
its like we cant use equations in the macro level and use it in the micro[atomic] level and vise versa
i.e every level is bizarre and every level is whole….i.e complete
summing up in simple words..:
whats happening is the deeper u go down or up… u dont have a clue of what the hell u r saying….as we can only have the resultants of the levels above and below of ‘our’ level.
and there can be infinite no: of things in each level of which we are not aware of since we only have the resultants.
and so there could me more than 11 dimensions we knw….
the universe is changing..
every lim t tends to 0 sec..
so the set of the universe can be rationally defined…
ie is there is no set of complete infinite universes…
i.e the universe is beyond all dimensions….
Thankx for reading and please comment..
and clarify any douts u hav….!!
- String Theory (askphysics.com)
- What is Existence? (otterthink.wordpress.com)
String theory suggests 11 dimensions. If the Big Bang involved a sudden expansion of three of those dimensions into the space we know today, is it possible that the energy for the Big Bang and subsequent expansion was caused by the collapse of one or more of the other 8 dimensions into the tiny form they allegedly inhabit today. The form of the
before the Big Bang is unknowable but is this hypothosis possible?
- String Theorists Simulate the Big Bang (livescience.com)
A thermodynamic variable may be intensive or extensive.
What are intensive variables?
The variables which are independent of size or amount of substance are called intensive variables.
Example: Density is an intensive variable. (because it does not depend on the amount of that substance)
What are extensive variables?
Example: Mass and volume are extensive variables. (Because they are directly measuring the amount of substance)
Why would you weigh more in a vacuum?
Vacuum doesn’t mean outer space. If you weigh yourself in vacuum on the surface of earth, you will weigh more because of the absence of Buoyancy. In the presence of air, weight decreases by the weight of displaced air.
Rain is falling vertically.A man running on the road keeps his umbrella tilted but a man standing on the street keeps his umbrella vertical to protect himslf frm the rain…But both of them keep their umbrella vertical to avoid sun-rays…