There are two conditions necessary for total internal reflection, which is when light hits the boundary between two mediums and reflects back into its original medium:
Light is about to pass from a more optically dense medium (slower) to a less optically dense medium (faster).
The angle of incidence is greater than the defined critical angle for the two mediums, which is given by:
θ = sin⁻¹(
/
)
Where θ = critical angle,
= refractive index of faster medium,
= refractive index of slower medium.
Choice C gives one of the above necessary conditions.
Answer:
u = 449 m/s
Explanation:
Given,
Mass of the bullet, m = 26 g
Mass of the wooden block,M = 4.7 Kg
height of the block,h = 0.31 m
initial speed of the block, u = ?
Using conservation of energy




v = 2.47 m/s
Now, using conservation of momentum to calculate the speed of the bullet.
m u + M u' = (M+m)v
m u = (M+m)v
0.026 x u = (4.7+0.026) x 2.47
u = 449 m/s
Hence, the speed of the bullet is equal to 449 m/s.
Answer:
option (a) 0.61 s
Explanation:
Given;
Time taken by the ball to reach the ground = 0.50 s
Let us first calculate the distance through which the ball falls on the ground
from the Newton's equation of motion, we have

where,
s is the distance
a is the acceleration
t is the time
here it is the case of free fall
thus, a = g = acceleration due to gravity
u = initial speed of the ball = 0
on substituting the values, we get

or
s = 1.225 m
Now,
when the elevator is moving up with speed of 1.0 m/s
the initial speed of the ball = -1.0 m/s (as the elevator is moving in upward direction)
thus , we have

or

or
4.9t^2 - t - 1.225 = 0
or
t = 0.612 s
hence, the correct answer is option (a) 0.61 s
Velocity is defined as Distance divided by Time.
In other words, V = D/T.
Now that we have our formula, we can solve.
Let's plug in the numbers we have.
We have 12m [East (direction not necessary when solving yet)] for our distance, and 0.15s as our time.
Divide the distance (12 /) by the time (0.15)
12 / 0.15 = 80.
Your velocity is 80 m/s [E]
I hope this helps!
Answer:
5p
Explanation:
We are given that a tin has 50 electrons.
We have to find in which subshell electrons experience the lowest effective nuclear charge.
We know that the electron in outermost shell experience the lowest effective nuclear charge.
Electronic configuration is given by

Outer most sub-shell is 5p. Therefore, 5p subshell experience the lowest effective nuclear charge because the distance of 5p sub-shell is large from nucleus.
Answer: 5p