Answer:
"h" signifies Planck's constant
Explanation:
In the equation energy E = h X v
The "h" there signifies Planck's constant
Planck's constant is a value, that shows the rate at which the energy of a photon increases/decreases, as the frequency of its electromagnetic wave changes.
It was named after Max Planck who discovered this unique relationship between the energy of a light wave and its frequency.
Planck's constant, "h" is usually expressed in Joules second
Planck's constant = 
Answer:
If a Gaussian surface is completely inside an electrostatic conductor, the electric field must always be zero at all points on that surface.
Explanation:
Option A is incorrect because, given this case, it is easier to calculate the field.
Option B is incorrect because, in a situation where the surface is placed inside a uniform field, option B is violated
Option C is also incorrect because it is possible to be a field from outside charges, but there will be an absence of net flux through the surface from these.
Hence, option D is the correct answer. "If a Gaussian surface is completely inside an electrostatic conductor, the electric field must always be zero at all points on that surface."
Answer:

we can see that this time period is independent of the mass of the child so answer would be same if the child mass is different
Explanation:
Natural frequency of a simple pendulum of L length is given as

so the time period of the oscillation is given as

so we will have



also from above formula we can see that this time period is independent of the mass of the child so answer would be same if the child mass is different
Gravity, acceleration, kinetic energy, the atmosphere
Answer:
a)F=3 x 10⁻⁷ N
b)x=2.405 m
Explanation:
Given that
m₁=295 kg
m₂=595 kg
d= 4.1 m
a)
m₃=63 kg
r=d/2 = 2.05 m
The force between the mass m₁ and m₃

by putting the values


F₁₃=2.94 x 10⁻⁷ N
The force between the mass m₂ and m₃
by putting the values


F₂₃=5.94 x 10⁻⁷ N
The net force F
F= F₂₃- F₁₃
F=5.94 x 10⁻⁷ N-2.94 x 10⁻⁷ N
F=3 x 10⁻⁷ N
b)
Lest take at distance x from mass m₂ net force is zero.


Form above two equation



x²=2.01(4.1-x)²
x=1.42 (4.1-x)
x=5.82 - 1.42x
x=2.405 m