Answer: C and D
Explanation: One of the first rule for total internal reflection to occur is that the ray must move from a dense to a less dense medium, hence refractive index of medium a must be greater than that of b.
When a ray moves from a dense to a less dense medium, the refracted ray moves away from the normal thus increasing the size of the angle of refraction (total internal refraction occurs when the angle of refraction is 90° and the angle of incidence at this point is known as the critical angle), hence the angle of incidence must be greater than the critical angle.
These points verifies option C and D
Wave speed = frequency * wavelength
Input the numbers into this equation :
Wave speed = 200 * 3
Work it out and you will get the answer :
Wave speed = 600 m/s
Answer:
18 radians
Explanation:
The computation is shown below:
As we know that
Torque = Force × Moment arm
= 1N × 1M
= 1N-M
Torque = 

Now

Here t = 1 minutes = 60 seconds
The temperature on the Earth would increase.
The temperature of the stratosphere would decrease.
Answer:
F = 50636.873 N
Explanation:
given,
bucket of water = 700-kg
length of cable = 20 m
Speed = 40 m/s
angle of the cable = 38.0°
let air resistance be = F
tension in rope be = T
T cos 38° = m×g..................(1)
..........(2)
equation (1)/(2)


F = 50636.873 N
Hence the force exerted on the bucket is equal to F = 50636.873 N