V^2=u^2 +2aS
U is found first by considering that first 8 secs and using v=u+at. {different v and u though}
V=-u+gt.
Magnitude of u = magnitude of v if there is no resistance ( because the conservation of energy says the k. E. must be the same when it passes you as when it left your hand).... up is negative here, down is positive.
V+v=gt
2v= g x 8
V=4xg.= the initial velocity for the next calculation
V^2=(4g)^2+(2xgx21)
So v can be calculated.
Answer:
As we keep on increasing the radius the value of the gravitation force of attraction decreases and as we decrease the radius the gravitation force increases.
Explanation:
Like the coulombs law of electrostatics, the law of gravitation also depends inversely on the square of the value of r. Therefore, as we keep on increasing the value of r the value of the gravitation force decreases and as we decrease the value of the r the value of gravitation force increases.
Gravitation Force=
Coulombs's Law= 
Shadows are the absence of light, they are created when an object blocks light. In other words, shadows are the product of light particles, known as photons. These particles “bounce off” of the object without reaching the other side. Therefore light by itself will not form a shadow.
In the outer layers of earths atmosphere gases are in ionized state primarily on account of cosmic rays . as earth rotates , strong electric current are set up due to movement of ions . these currents form earth magnetic field . and thus two equal and opposite poles of earth formed
Answer:
(A) Total energy will be equal to 
(b) Energy density will be equal to 
Explanation:
We have given diameter of the plate d = 2 cm = 0.02 m
So area of the plate 
Distance between the plates d = 0.50 mm = 
Permitivity of free space 
Potential difference V =200 volt
Capacitance between the plate is equal to 
(a) Total energy stored in the capacitor is equal to


(b) Volume will be equal to
, here A is area and d is distance between plates

So energy density 