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3 years ago

What are two uses of total internal reflection? (GCSE Physics)

Physics

1 answer:

jeka943 years ago

3 0

Answer:

1) Used in optical instruments such as telescopes.

2) Used to form mirages

Explanation:

1) Perhaps the simplest example of this is the astronomical refractor telescope with a right-angle eyepiece holder. Astro scopes mostly point at things high in the sky, but it is inconvenient to place your eye low to look up through the scope, so the light path is bent 90 degrees just before the eyepiece. This can be done with a mirror, but using a simple 45 degree prism (internal angles 45, 45, and 90 degrees) will do the 90 degree bend more efficiently.

2) So when a light pass from cold air to hot air light tends to bend from its path which is known as refraction. As the light get refracted it reaches to a point where the light tends to form 90 degree angle.

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A baseball pitcher throws a ball horizontally at a speed of 34.0 m/s. A catcher is 18.6 m away from the pitcher. Find the magnit

Sidana [21]

To develop this problem, it is necessary to apply the concepts related to the description of the movement through the kinematic trajectory equations, which include displacement, velocity and acceleration.

The trajectory equation from the motion kinematic equations is given by

$y = \frac{1}{2} at^2+v_0t+y_0$

Where,

a = acceleration

t = time

$v_0$ = Initial velocity

$y_0$ = initial position

In addition to this we know that speed, speed is the change of position in relation to time. So

$v = \frac{x}{t}$

x = Displacement

t = time

With the data we have we can find the time as well

$v = \frac{x}{t}$

$t = \frac{x}{v}$

$t = \frac{18.6}{34}$

$t = 0.547s$

With the equation of motion and considering that we have no initial position, that the initial velocity is also zero then and that the acceleration is gravity,

$y = \frac{1}{2} at^2+v_0t+y_0$

$y = \frac{1}{2} gt^2+0+0$

$y = \frac{1}{2} gt^2$

$y = \frac{1}{2} 9.8*0.547^2$

$y = 1.46m$

Therefore the vertical distance that the ball drops as it moves from the pitcher to the catcher is 1.46m.

6 0

3 years ago

4. A family leaves from New York City and is flying to Los Angles which is 2800mi away. It takes

Blizzard [7]

The average speed of the whole travel is equal to <u>400 mph</u>.

Why?

From the statement, we know that whole travel is divided into three parts. For the first part (traveling from New York to Chicago), we have that it was 3.25 hours and the covered distance was half of the total distance (1400mi). For the second part, we have that it was 1 hour (layover time), and the covered no distance. For the third part (traveling from Chicago to Los Angeles), we have that it was 2.75 hours, and it took the other half of the total distance (1400mi).

We can calculate the average speed of the whol travel using the following formula:

$AverageSpeed=\frac{distance_{1}+distance_{2}+distance_{3}}{time_{1}+time{2}+time_{3}}$

Now, substituting and calculating, we have:

$AverageSpeed=\frac{1400mi+0mi+1400mi}{3.25h+1h+2.75h}$

$AverageSpeed=\frac{2800mi}{7h}=400mph$

Hence, we have the average speed of the whole travel is equal to 400 mph.

Have a nice day!

7 0

4 years ago

How do I solve this problem

PilotLPTM [1.2K]

Answer:

it is light

Explanation:

the arrow that says light is on the glass it must be near from tungsten

5 0

3 years ago

An 80.0 kg skier slides down a hill shaped as shown. Assume

umka21 [38]

The height above the ground from where the skier start is 11.5 m.

<h3>Conservation of energy</h3>

The height above the ground from where the skier start is determined by applying the principle of conservation of energy as shown below;

P.E = K.E

mgh = ¹/₂mv²

gh = ¹/₂v²

$h = \frac{v^2}{2g} \\\\h = \frac{15^2}{2 \times 9.8} \\\\h = 11.5 \ m$

Thus, the height above the ground from where the skier start is 11.5 m.

Learn more about conservation of energy here: brainly.com/question/166559

8 0

3 years ago

Jin knows that the initial internal energy of a closed system is 78 J and the final internal energy is 180 J. He also knows that

lawyer [7]

As we know by the first law of thermodynamics

$Q = \Delta U + W$

here we know that

Q = heat given to the system

$\Delta U = U_f - U_i$

W = work done by the system

now here we can say

$\Delta U = 180 - 78 = 102 J$

$W = 64 J$

now we can say that heat will be given as

$Q = 64 + 102 = 166 J$

now here we can say that Jin does the error in his first step while calculation of change in internal energy as he had to subtract it while he added the two energy

So best describe Jin's Error is

<em>B )For step 1, he should have subtracted 78 J from 180 J to find the change in internal energy. </em>

8 0

3 years ago