Please help I found this confusing

Light travels from medium X into medium Y. Medium Y has a higher index of refraction. Consider each statement below:(i) The ligh

ahrayia [7]

Answer:

i) FALSE, ii) TRUE, iii) FALSE, iv) FALSE

Explanation:

When light (electromagnetic radiation) travels through a material medium, its speed is less than the speed of light in a vacuum. If we define the index of parts

n = c / v

where v is the speed of light in the material medium.

The direction of the ray can be determined by the law of refraction

n₁ sin θ₁ = n₂ sin θ₂

Let's apply these equations to our case where

nₓ <n_y

i) The expression of the refractive index

nₓ < n_y

$\frac{c}{v_x} = \frac{c}{n_y}$

v_y <vₓ

therefore the expression is FALSE

ii) If we use the law of refraction, the light, when passing from a medium with a lower start to another with a higher index, must approach the normal one, away from what would be the continuation of the path of the incident ray

so the expression is TRUE

iii) The speed of light is constant in all material media

the statement is FALSE

iv) light approaches normal

Let me clarify that the normal is a line perpendicular to the surface at the point of contact, not the direction of Io.

the statement of FALSE

8 0

3 years ago

In order to increase the kinetic energy of a speeding train by 44%, 42MJ of work must be performed (1 MJ = 106 J). If the final

victus00 [196]

Answer:

Explanation:

100 % increase makes an amount 2 times .

44 % increase = 42 MJ

100 % increase = 95.45 MJ

final kinetic energy = 2 x 95.45 MJ

= 190.9 x 10⁶ J

1/2 m v² = 190.9 x 10⁶

.5 x m x 9² = 190.9 x 10⁶

m = 4.71 x 10⁶ kg

= 4710 metric ton .

7 0

3 years ago

For part 2 I was told that The circuit below will accommodate up to three resistors in series. Explore the circuit. It is a seri

Amiraneli [1.4K]

(a) Draw the circuit diagram for the three resistors in series that you assembled in Part 2. Label the voltage and the resistances of each resistor

The diagram will look like the following:

As all the resistors are equal, their voltage drop will also be equal, which will be a third of the input voltage

(b) For the three resistors in series, how did the measured total voltage, current across each resistor, total current, and voltage drop across each resistor compare to the values that you calculated?

The value of the measured voltage on each resistor can be seen as to be exactly as calculated, which is 1/3 of the voltage input. The total current can be calculated as:

$I=\frac{V}{R+R+R}=\frac{15}{3*3}=\frac{15}{9}\approx1.7A$

Which is the one seen on the amperimeter

(c) How did the equivalent resistance, voltage drop across each resistor, total current, and total voltage change as you added resistors in series to the circuit?

The voltage drop on each resistor will decrease once you add more resistors, as there will be more total resistance, and thus less current. As the resistance of each resistor is constant, the relation V=RI given by Ohm's law will be reduced.

5 0

1 year ago

What is the definition of energy

Contact [7]

Energy is the ability to do work.

5 0

3 years ago

Read 2 more answers

An astronaut goes out for a space walk. Her mass (including space suit, oxygen tank, etc.) is 100 kg. Suddenly, disaster strikes

Marina CMI [18]

Answer:

Part A:

Unknown variables:

velocity of the astronaut after throwing the tank.

maximum distance the astronaut can be away from the spacecraft to make it back before she runs out of oxygen.

Known variables:

velocity and mass of the tank.

mass of the astronaut after and before throwing the tank.

maximum time it can take the astronaut to return to the spacecraft.

Part B:

To obtain the velocity of the astronaut we use this equation:

-(momentum of the oxygen tank) = momentum of the astronaut

-mt · vt = ma · vt

Where:

mt = mass of the tank

vt = velocity of the tank

ma = mass of the astronaut

va = velocity of the astronaut

To obtain the maximum distance the astronaut can be away from the spacecraft we use this equation:

x = x0 + v · t

Where:

x = position of the astronaut at time t.

x0 = initial position.

v = velocity.

t = time.

Part C:

The maximum distance the astronaut can be away from the spacecraft is 162 m.

Explanation:

Hi there!

Due to conservation of momentum, the momentum of the oxygen tank when it is thrown away must be equal to the momentum of the astronaut but in opposite direction. In other words, the momentum of the system astronaut-oxygen tank is the same before and after throwing the tank.

The momentum of the system before throwing the tank is zero because the astronaut is at rest:

Initial momentum = m · v

Where m is the mass of the astronaut plus the equipment (100 kg) and v is its velocity (0 m/s).

Then:

initial momentum = 0

After throwing the tank, the momentum of the system is the sum of the momentums of the astronaut plus the momentum of the tank.

final momentum = mt · vt + ma · va

Where:

mt = mass of the tank

vt = velocity of the tank

ma = mass of the astronaut

va = velocity of the astronaut

Since the initial momentum is equal to final momentum:

initial momentum = final momentum

0 = mt · vt + ma · va

- mt · vt = ma · va

Now, we have proved that the momentum of the tank must be equal to the momentum of the astronaut but in opposite direction.

Solving that equation for the velocity of the astronaut (va):

- (mt · vt)/ma = va

mt = 15 kg

vt = 10 m/s

ma = 100 kg - 15 kg = 85 kg

-(15 kg · 10 m/s)/ 85 kg = -1.8 m/s

The velocity of the astronaut is 1.8 m/s in direction to the spacecraft.

Let´s place the origin of the frame of reference at the spacecraft. The equation of position for an object moving in a straight line at constant velocity is the following:

x = x0 + v · t

where:

x = position of the object at time t.

x0 = initial position.

v = velocity.

t = time.

Initially, the astronaut is at a distance x away from the spacecraft so that

the initial position of the astronaut, x0, is equal to x.

Since the origin of the frame of reference is located at the spacecraft, the position of the spacecraft will be 0 m.

The velocity of the astronaut is directed towards the spacecraft (the origin of the frame of reference), then, v = -1.8 m/s

The maximum time it can take the astronaut to reach the position of the spacecraft is 1.5 min = 90 s.

Then:

x = x0 + v · t

0 m = x - 1.8 m/s · 90 s

Solving for x:

1.8 m/s · 90 s = x

x = 162 m

The maximum distance the astronaut can be away from the spacecraft is 162 m.

6 0

3 years ago

Please help I found this confusing​

Please help I found this confusing