Answer:
at r < R;
at 2R > r > R;
at r >= 2R
Explanation:
Since we have a spherically symmetric system of charged bodies, the best approach is to use Guass' Theorem which is given by,
(integral over a closed surface)
where,
= Electric field
= charged enclosed within the closed surface
= permittivity of free space
Now, looking at the system we can say that a sphere(concentric with the conducting and non-conducting spheres) would be the best choice of a Gaussian surface. Let the radius of the sphere be r .
at r < R,
= 0 and hence = 0 (since the sphere is conducting, all the charges get repelled towards the surface)
at 2R > r > R,
= Q,
therefore,
(Since the system is spherically symmetric, E is constant at any given r and so we have taken it out of the integral. Also, the surface integral of a sphere gives us the area of a sphere which is equal to 
)
or,
at r >= 2R
= 2Q
Hence, by similar calculations, we get,
Explanation:
Work done by winch = kinetic energy of car
∫ T ds = ½ mv²
∫ 225s ds = ½ mv²
225/2 s² = ½ mv²
225 s² = mv²
v = 15s / √m
Given s = 10 m and m = 2500 kg:
v = 15 (10) / √2500
v = 3 m/s
Answer:
Naturally occurring radio waves are made by lightning or by astronomical objects. Artificially generated radio waves are used for fixed and mobile radio communication, broadcasting, radar and other navigation systems, communications satellites, computer networks and innumerable other applications.
Explanation:
let the distance of pillar is "r" from one end of the slab
So here net torque must be balance with respect to pillar to be in balanced state
So here we will have
here we know that
mg = 19600 N
Mg = 400,000 N
L = 20 m
from above equation we have
so pillar is at distance 10.098 m from one end of the slab
