C
Because in my opinion they do bending of a light wave as it passes at an angle from one medium to another.
Answer: 45.3°
Explanation:
Given,
Length of ladder = l
Weight of ladder = w
Coefficient of friction = μs = 0.495
Smallest angle the ladder makes = θ
If we assume the forces in the vertical direction to be N1, and the forces in the horizontal direction to be N2, then,
N1 = mg and
N2 = μmg
Moment at a point A in the clockwise direction is
N2 Lsinθ - mg.(L/2).cosθ = 0
μmgLsinθ - mg.(L/2).cosθ = 0
μmgLsinθ = mg.(L/2).cosθ
μsinθ = cosθ/2
sin θ / cos θ = 1 / 2μ
Tan θ = 1 / 2μ
Substituting the value of μ = 0.495, we have
Tan θ = 1 / 2 * 0.495
Tan θ = 1 / 0.99
Tan θ = 1.01
θ = tan^-1(1.01)
θ = 45.3°
The correct option is A.
J.J Thompson proposed the plum model of atomic structure. The model states that the atom is a sphere of positively charged matter in which electrons are embedded.
Rutherford designed an experiment to verify the truth of this model. He set up a beam of alpha particles which are to be passed a thin gold foil. If the JJ model of atomic structure is correct, all of the alpha particles suppose to pass through the foil, but some of the alpha particles bounced back while those that passed through the foil emerged at different angles.
