A charge Q is divided in two parts q and Q - q separated by a distance R. If force between the two charges is maximum, find the relationship between q & Q.
Solution: F=K q(Q-q)/r2
for max. &min.dF/dq=0 , q=Q/2
Question2:A circular disc X of radius R is made from an iron pole of thickness t, and another disc Y of radius 4R is made from an iron plate of thickness t/4. then the relation between the moment of inertia Ix and Iy is
(D) None of these
If t is the thickness and R is the radius of the disc, then mass = πR2tρ
ρ = density of the material of the disc.
Moment of inertia of disc X,
Moment of inertia of disc Y,
From equation (i) and (ii)
On a planet a freely falling body takes 2 sec when it is dropped from a height of 8 m, the time period of simple pendulum of length 1 m on that planet is
On a planet, if a body dropped initial velocity (u = 0) from a height h and takes time t to reach the ground
A car is moving with uniform velocity on a rough horizontal road. Therefore, according to Newton's first law of motion
(a) No force is being applied by its engine
(b) An acceleration is being produced in the car
(c) The kinetic energy of the car is increasing
(d) force is surely being applied by its engine
Solution4: d Since, force needed to overcome frictional force
A particle is projected upwards. The times corresponding to height h while ascending and while descending are a and b respectively.Find the velocity of projection
If a and b are time of ascent and descent respectively then time of flight
Class 9 physics notes on chapter motion is now available at the following link CLASS 9 MOTION NOTES (FULL LENGTH)
Question1: A charge Q is divided in two parts q and Q - q separated by a distance R. If force between the two charges is maximum, find the ...
Coherent sources are those sources of light which emit continous light waves of same wavelength , same frequency and are in same phase or h...
Our New Free physics ebooks (pdfs) are available at this link . Hope you lile them.
Unit I: Physical World and Measurement (Periods 10) Physics: Scope and excitement; nature of physical laws; Physics, technology and society...
ADVANTAGES The generation of A.C. is cheaper than that of D.C. A.C. machines are simple , robust and do mot require much attention for the...
Hi all here in this article i am giving some tips and tricks to solve problems in mechanics. To master problem solving skill you need to pra...
1.A particle moves in a straight line with retardation proportional to its displacement. Its loss of kinetic energy for any displacement x i...
Many times i have had users ask me a question which book to opt between H.C Verma Concepts of physics and NCERT physics books . My answer ...
Unit I: Electrostatics (Periods 25) Electric charges and their conservation. Coulomb’s law – force between two point charges, forces betwee...