A. B. D. C. D, A, A, C, B, B, D, D
Answer:
2.85 s .
Explanation:
y(t) = y(0) + v₀t + 1/2 gt²
y(t) is vertical displacement , y(0) is initial position , v₀ is initial velocity and t is time required to make vertical displacement and g is acceleration due to gravity.
Here y(0) is zero , v₀ = 14 m/s , g = 9.8 m s⁻² , y(t ) = 0 , as the pumpkin after time t comes back to its initial position, that is ground .
We shall take v₀ as negative as it is in upward direction and g as positive as it acts in downward direction
Put the values in the equation above,
0 = 0 - 14t + 1/2 x 9.8 t²
14 t = 1/2 x 9.8 t²
t = 28 / 9.8
t = 2.85 s .
Statement three i do believe
Answer:
The answer is explained below.
Explanation:
The energy emitted during the de-excitation of an electron from a higher energy level to a lower energy level is directly proportional to the frequency of the emitted light.
Here, the total sum of the energies of 2 frequencies of light emitted in different stages is equal to the energy of a single frequency of light during the de-excitation of fourth level to ground level directly.
Hence the total sum of of the frequencies of 2 lights emitted in different stages is equal to the frequency of single frequency of light emitted during the de-excitation from fourth level to ground level directly.
The some of the energies of 2 frequencies emitted by one electron is equal to the energy of a single frequency when electron jumps directly.
Answer:
The product of (wavelength) x (frequency) is always the same number ... the wave's speed.
So if the wavelength is somehow reduced to 1/4 its original length, the frequency is immediately multiplied by 4 . That's the only way their product can remain the same.
Explanation:
