Answer:
Colour of any object is by the colour of light it reflects i.e if white light is incident on the object,it will reflect blue color.so it will appear blue.But if red light is incident on it,it will not reflect that and absorb it.so as it will not reflect any light it will appear black.
Explanation:
Answer:
3.962
Explanation:
mass = 1.2
gravity g = 9.81
velocity = ?
mgh = 1/2mv² + 1/2(1/2)mv²
= 9.81 x 1.2 = 3/4v²
11.772 x 4 = 3/4v²
47.088 = 3v²
divide through both sides by 3
15.696 = v²
take the square root of both sides
√15.696 = √v²
= 3.6962 = v
the speed is therefore 3.692
Answer:

Explanation:
As we know by Bernoulli's principle


here we know that

also we know that


now we have


Answer:
L = 44,096 m
Explanation:
The speed of the sound wave is constant therefore we can use the relations of uniform kinematics
v = x / t
the speed of the wave in the bar is
v = 15 v or
v = 15 343
v = 5145 m / s
The sound at the bar goes the distance
L = v t
Sound in the air travels the same distance
L = v_air (t + 0.12)
as the two recognize the same dissonance,
v t = v_air (t +0.12)
t (v- v_air) = 0.12 v_air
t = 0.12 v_air / (v -v_air)
l
et's calculate
t = 0.12 343 / (5145 - 343)
t = 8.57 10-3 s
The length of the bar is
L = 5145 8.57 10-3
L = 44,096 m