Answer: Why does the cord of an electric heater not glow while the heating element does? The heating element of the heater is made up of alloy which has very high resistance so when current flows through the heating element, it becomes too hot and glows red. But the resistance of cord which is usually of copper or aluminum is very low so it does not glow.
Explanation:
Answer:
4.7m
Explanation:
Given parameters:
Mass of the book = 1kg
Gravitational potential energy = 46J
Unknown:
Height of the shelf = ?
Solution:
The potential energy is due to the position of a body above the ground.
Gravitational potential energy = mgh
m is the mass,
g is the acceleration due gravity = 9.8m/s²
h is the height which is unknown
46 = 1 x 9.8 x h
h = 4.7m
Answer:
(A) It will take 22 sec to come in rest
(b) Work done for coming in rest will be 0.2131 J
Explanation:
We have given the player turntable initially rotating at speed of 
Now speed is reduced by 75 %
So final speed 
Time t = 5.5 sec
From first equation of motion we know that '

(a) Now final velocity 
So time t to come in rest 
(b) The work done in coming rest is given by

Answer:
Explanation:
The application of Gauss's law is used in the derivation as shown with detailed step by step in the attached file.
The potential difference on this spherical capacitor is ΔV = Va - Vb = kQ/a - kQ/b = kQ(1/a - 1/b)