Answer:
critical angle is the angle of incidence in optically denser medium, for which the angle of reflection in the less denser medium is 90 degree
Explanation:
total internal reflection occurs at one particular angle of incidence where the reflected ray lies on the boundary.
this angle is called the critical angle
Answer:
Here's what I get
Explanation:
A. Distance between A and B.
h = -½gt²
The stones go faster the farther they fall.
Stone A has already reached 5 m when B is released.
When B reaches 5 m, A has dropped further and is falling even faster.
The distance between the stones increases with time.
Figure 1 shows this effect in a graph of height vs. time.
B. Speed of Stone B
v² = 2gh =2 × ( -9.81 m·s⁻²) × (-5 m) = 98.1 m·s⁻²
v = 9.9 m/s
The stone is travelling at 9.9 m/s when it reaches 5 m.
C. Velocity vs time
v = -gt
Both stones accelerate at the same rate.
When Stone B has reached 10 m at time t, Stone A is falling much faster.
Fig. 2 shows this in a graph of velocity vs time.
<span>The speed at which you fall does play a role in the severity, but it also depends on the way that you hit the ground. Falling flat on your face or chest at high speeds will most likely lead to death. However, if you fall looking up towards the sky and don't hit your head, you have a greater chance of only walking away with injuries. It is possible to be killed from a fall of a minuscule distance if impact is made and causes brain damage or an artery to burst. There is less than a 1% chance that someone will survive if this is the case.</span>