Great question. Albert Einstein proved that light acts as both a particle and a wave in his 1905 paper. This is called wave-particle duality.
With quantum mechanics, it is easy to prove that light behaves as both a particle and a wave.
When UV light hits a metal surface, it causes an emission of electrons. This "photoelectric effect" proves how light behaves.
Answer:
C) 6 m/s
Explanation:
Given that
m₁=5000 kg
The initial velocity of 5000 kg car =u₁
m₂=10,000 kg
The initial velocity of 10000 kg car =u₂ = 0 m/s
After collision the final speed of the both car,v = 2 m/s
There is no any external force on the system that is why linear momentum will be conserved.
Linear momentum P = m v
m₁u₁ + m₂u₂ = (m₂ + m₁) v
5000 x u₁ + 10000 x 0 = (5000 + 10000) x 2
5000 x u₁ = 15000 x 2
5 x u₁ = 15 x 2
u₁ = 6 m/s
Therefore the answer is C.
C) 6 m/s
Answer:
The Flemings left hand rule is used to find the magnitude of a magnetic force
Explanation:
Fleming's left hand rule states that if the first three fingers are held mutually at right angles to one another, then the fore finger points into the direction of magnetic field the middle finger in the direction of current while the thumb points in the direction of force.
Mathematically
Magnetic Force F= BILsinθ
Where
B= magnetic field density Tesla
I= current
L= length of conductor
θ= angle of conductor with field
Answer:
A) E = 4.96 x 10³ eV
B) E = 4.19 x 10⁴ eV
C) E = 3.73 x 10⁹ eV
Explanation:
A)
For photon energy is given as:


where,
E = energy of photon = ?
h = 6.625 x 10⁻³⁴ J.s
λ = wavelength = 0.25 nm = 0.25 x 10⁻⁹ m
Therefore,

<u>E = 4.96 x 10³ eV</u>
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B)
The energy of a particle at rest is given as:

where,
E = Energy of electron = ?
m₀ = rest mass of electron = 9.1 x 10⁻³¹ kg
c = speed of light = 3 x 10⁸ m/s
Therefore,


<u>E = 4.19 x 10⁴ eV</u>
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C)
The energy of a particle at rest is given as:

where,
E = Energy of alpha particle = ?
m₀ = rest mass of alpha particle = 6.64 x 10⁻²⁷ kg
c = speed of light = 3 x 10⁸ m/s
Therefore,


<u>E = 3.73 x 10⁹ eV</u>
It would take millions of years to form a mountain as plates move very slowly and to form it first one plate should climb upon another. After this very slowly this hill will convert into a mountain.