Explanation:
A.
Using the wave equation:
v = d/t
Where,
v = velocity
d = distance
= 23.5 km
= 23500 m
t = time
= 2m 30s = 150 s
v = 23500/150
= 156.7 m/s
B.
From the calculated value above, it can be seen that the velocity of the heat blast is >>> than the velocity of sound above sea level.
Answer:
76
At what angle height and range of projectile are equal?
It means that the range of the projectile with a given initial velocity is same for a pair of projection angles θ and 90° – θ.
The answer is already in the blank for, its was greater
Answer:
14 cm
Explanation:
Power of eye = 57.1 D
The relation between the focal length and the power is
f = 1 / P = 1 / 57.1 = 0.0175 m = 1.75 cm
The distance between the image and the lens is, v = 2 cm
Let the distance between the object and the eye is u
Use the lens equation
1/ f = 1 / v - 1 / u
1 / 1.75 = 1 / 2 - 1 / u
1 / u = 1 / 2 - 1 / 1.75
1 / u = (1.75 - 2) / 3.5
u = - 14 cm
Thus, the distance between the feature and eye is 14 cm .
When light is reflected by a mirror, the angle of incidence is always <span>A. equal to the angle of reflection. We know this by the Law of Reflection.</span>
