(B) 2.25cm
<u>Explanation:</u>
Given:
At 40 hours, the height of the bamboo plant is 2.1cm
At 50 hours, the height of the bamboo plant is 2.4cm
Height of the bamboo plant after 45 hours = ?
The difference in length from 40 to 50 hours = 2.4 - 2.1cm
= 0.3 cm
Mean of 40 and 50 is 45.
Thus,
At 45 hours, the height will increase by 0.3/2
= 0.15 cm
Height at 45 hour = 2.1 + 0.15cm
= 2.25cm
Therefore, the height of the plant after 45 hours is 2.25cm
Answer : The wavelength of photon is, 
Explanation : Given,
Energy of photon = 
Formula used :

As, 
So, 
where,
= frequency of photon
h = Planck's constant = 
= wavelength of photon = ?
c = speed of light = 
Now put all the given values in the above formula, we get:


Conversion used : 
Therefore, the wavelength of photon is, 
Answer:
θ = Cos⁻¹[A.B/|A||B|]
A. The angle between two nonzero vectors can be found by first dividing the dot product of the two vectors by the product of the two vectors' magnitudes. Then taking the inverse cosine of the result
Explanation:
We can use the formula of the dot product, in order to find the angle between two non-zero vectors. The formula of dot product between two non-zero vectors is written a follows:
A.B = |A||B| Cosθ
where,
A = 1st Non-Zero Vector
B = 2nd Non-Zero Vector
|A| = Magnitude of Vector A
|B| = Magnitude of Vector B
θ = Angle between vector A and B
Therefore,
Cos θ = A.B/|A||B|
<u>θ = Cos⁻¹[A.B/|A||B|]</u>
Hence, the correct answer will be:
<u>A. The angle between two nonzero vectors can be found by first dividing the dot product of the two vectors by the product of the two vectors' magnitudes. Then taking the inverse cosine of the result</u>