All categories

3 years ago

A light ray hits a plane surface at 20 degrees. What is the angle between the incident and reflected rays.

Physics

1 answer:

Eduardwww [97]3 years ago

7 0

Answer:

140°

Explanation:

The law of reflection states that the angle of redlection equals to the angle of incidence.

When light rays hit surface at 20°, they also leave the surface at the same angle

Since the whole surface has 180° then subtracting these two angles from total angle gives the the angle between the incident and reflected rays.

180°-20°-20°=140°

The angle of incidence and reflection are equal hence 140/2=70°

The question needed the angle between the incident and reflected rays which is already calculated as 140°

You might be interested in

A 52 kg and a 95 kg skydiver jump from an airplane at an altitude of 4750 m, both falling in the pike position. Assume all value

Scilla [17]

Answer: 52 kg skydiver: 9.09 m/s and 522.55 s

95 kg skydiver: 12.3 m/s and 386.2 s

Explanation: Drag Force is an opposite force when an object is moving in a fluid.

For skydivers, when falling through the air, the forces acting on it are gravitational and drag forces. At a certain point, drag force equals gravitational force, which is constant on any part of the planet, producing a net force that is zero. Since there is no net force, there is no acceleration and, consequently, velocity is constant. When that happens, the person reached the Terminal Velocity.

Drag Force and Velocity are proportional to the squared speed. So, terminal velocity is given by:

$F_{G}=F_{D}$

$mg=\frac{1}{2}C \rho Av_{T}^{2}$

$v_{T}=\sqrt{\frac{2mg}{\rho CA} }$

where

m is mass in kg

g is acceleration due to gravitational force in m/s²

ρ is density of the fluid in kg/m³

C is drag coefficient

A is area of the object in the fluid in m²

Calculating:

The 52kg skydiver has terminal velocity of:

$v_{T}=\sqrt{\frac{2(52)(9.8)}{(1.21)(0.7)(0.14)} }$

$v_{T}=$ 9.09

The 95kg skydiver's terminal velocity is

$v_{T}=\sqrt{\frac{2(95)(9.8)}{(1.21)(0.7)(0.14)} }$

$v_{T}=$ 12.3

The 52 kg and 95kg skydivers' terminal velocity are 9.09m/s and 12.3m/s, respectively.

The time each one will reach the floor will be:

52 kg at 9.09 m/s:

$t=\frac{4750}{9.09}$

t = 522.5

95 kg at 12.3 m/s:

$t=\frac{4750}{12.3}$

t = 386.2

The 52 kg and 95kg skydivers' time to reach the floor are 522.5 s and 386.2 s, respectively.

3 0

3 years ago

What is the current when the resistance is 5 ohms and the voltage is 10 volts?

Travka [436]

Ohm's Law states V = IR
So,
I = V/R
The answer is B. 10/5=2 amps

5 0

3 years ago

Read 2 more answers

What happens if an air conditioner is used in a house that is not well insulated and not well scaled? Explain in terms of energy

stira [4]

It will use a lot more energy (electricity) to cool down the room. Because heat energy from outside the room can easily transfer into the room again if the room is not well insulated. So more energy is needed to cool down the room again

4 0

3 years ago

A metal rod of length (L) moves with velocity (v), perpendicular to its length, in a magnetic field B, which is perpendicular to

Alborosie

Explanation:

If a metal rod of length L moves with velocity v is moving perpendicular to its length, in a magnetic field B, the induced emf is given by :

$\epsilon=Blv$

The electric field in the conductor is given by :

$E=\dfrac{\epsilon}{l}\\\\E=\dfrac{Blv}{l}\\\\E=Bv$

It is clear that the electric field is independent of the length of the rod. If the length of the rod is doubled, the electric field in the rod remains the same.

6 0

3 years ago

What does a Lewis structure diagram represent?

densk [106]

Answer:

correct me if i'm wrong nut i thinks its a The atomic symbol of an element surrounded by valence electrons

Explanation:

5 0

3 years ago

Read 2 more answers