Physics test 1 grade 10

Question 1

What is the difference between luminous and non-luminous objects?
+ examples

Answer 1

Luminous objects, for example, computers or tvs, emit their own light, while non luminous objects, such as chairs or paper, rely on other sources of light to become visible to humans. The external light source bounces off of the non luminous object and reflects into our eyes, allowing us to see.

Luminous examples: computers, TVs; Non-luminous examples: chairs, paper

Luminous examples: computers, TVs; Non-luminous examples: chairs, paper.

Question 2

Fill in the blank: Some objects look black because they _______ the light.

Answer 2

absorb

Question 3

Describe how the reflection at a mirror differs from that at a non-mirror.

Answer 3

Non-mirrors reflect light in all directions due to uneven surfaces, while mirrors reflect light regularly due to their smoothness.

Question 4

Why do some things appear transparent?

Answer 4

They allow the light to pass directly through them.

Question 5

What evidence justifies modeling light as a wave?

Answer 5

When water waves pass through a small gap, they spread out and diffract

Question 6

What is monochromatic light?

Answer 6

Light made up of only one color (one wavelength)

This implies one wavelength.

Question 7

How fast does light travel?

Answer 7

300,000,000 m/s (300,000 km/s)

Question 8

How long does light take to travel 1 km?
+ calculation

Answer 8

0.000003 seconds

1/300,000

Question 9

Why can we call the travel time of light an ‘instant’?

Answer 9

Due to its incredible speed, it seems instantaneous to humans.

Question 10

How fast does sound travel

Answer 10

343 m / s

Calculation: 1000/3.

Calculation: 1000/3.

Question 11

If an observer counts 10 seconds between seeing lightning and hearing thunder, how far away was the flash?

Answer 11

3.3 km

Calculation: 10/3.

Calculation: 10/3.

Question 12

Would the method of measuring distance using light and sound work on another planet?

Answer 12

No, conditions such as temperature and magnetic fields may cause differences.

Question 13

How long does it take light to reach Earth from Mars? (Mars is 54.6 million km away)

Answer 13

182 seconds or around 3 minutes

Calculation: 54.6 million / 300,000

Calculation: 54.6 million / 300,000.

Question 14

Fill in the blank: Light can travel through _______.

Answer 14

empty space

Question 15

What happens to light when it strikes white paper?

Answer 15

It diffuses and bounces off in all directions.

Question 16

What happens when light strikes black paper?

Answer 16

The paper absorbs it.

Question 17

What is the speed of light in meters per second?

Answer 17

300,000,000 m/s

Question 18

What is the wavelength of violet light?

Answer 18

0.0004 mm

Question 19

What is the wavelength of red light?

Answer 19

0.0007 mm

Question 20

What does light transfer when it interacts with materials?

Answer 20

Energy
- energy is required to make light

Energy is needed to produce light.

Question 21

What are the four reflections associated with light

Answer 21

Transmission, diffuse reflection, regular reflection, absorption

Question 22

examples of non luminous objects

Answer 22

chair, bed, a waterbottle

Question 23

how do we see non luminous objects

Answer 23

We see non luminous objects because light, including daylight and other sources, bounce off of the object and some of it goes into our eyes. These objects do not emit light, rather reflect it, allowing us to see them.

Question 24

why do we see colors

Answer 24

Different
wavelengths
are received by our eye and interpreted
by our brain as different colors

Question 25

White light

Answer 25

White light is made up of a mixture of wavelengths.

Question 26

Evidence that light travels in straight lines

Answer 26

Evidence that light travels in straight lines includes the path of light that a laser or a sunbeam produces

Question 27

Diffuse reflection

Answer 27

If a surface is rough, diffuse reflection. happens. Instead of forming an image, the reflected light is scattered in all directions. This may cause a distorted image of the object, as occurs with rippling water, or no image at all

Question 28

Regular reflection

Answer 28

when the light falls on the smooth, shiny surface and reflects entirely within the same angle.

Question 29

absorption

Answer 29

the process in which light is absorbed and converted into energy

Question 30

transmission

Answer 30

when light travels through a material completely, like space, air, water, and clear glass

Question 31

visible light

Answer 31

all wavelengths of light that the human eye can detect

Question 32

incandescence

Answer 32

production of visible light by an object so hot that it glows

Question 33

luminescence

Answer 33

production of visible light without heat

Question 34

types of luminescence

Answer 34

fluorescence, electroluminescence, bioluminescence

Question 35

fluorescence

Answer 35

a substance absorbes shorter wavelength ultraviolet light and emits light in a visible range of wavelengths (gemstones)

Question 36

electroluminescence

Answer 36

a substance that gives off light when al electrical current passes through it (neon gas)

Question 37

bioluminescence

Answer 37

production of light by living things as a result of a chemical reaction(s) (fireflies, jellyfish)

Question 38

How does light interact with matter

Answer 38

transparent, translucent, or opaque matter

Question 39

refraction

Answer 39

occurs when light changes direction as it passes into a new medium and changes speed

Question 40

scattering

Answer 40

occurs when light bumps into tiny particles of matter and spreads out

Question 41

types of transmission

Answer 41

refraction, scattering

Question 42

why would matter heat up when light is pointed at it

Answer 42

due to the transfer of energy

Question 43

transparent matter

Answer 43

matter that transmits light without scattering it

Question 44

translucent matter

Answer 44

matter that transmits light but scatters it as it passes through

Question 45

opaque

Answer 45

matter that doesn't let light pass through

Question 46

features of light (6)

Answer 46

it is a form of radiation it travels in straight lines it transfers energy it behaves like waves it travels through empty space (no medium required) it is the fasted thing

Question 47

how does light travel

Answer 47

Light exhibits characteristics of both waves and particles, the latter of which are described as packets of energy called photons. These waves, or photons, travel in narrow beams called rays. Only when light rays move from one medium to another, such as from air to water, are their linear paths altered.

Question 48

what is diffraction

Answer 48

the spreading of waves as they pass through or around an obstacle.

Question 49

Distance, speed, time triangle

Answer 49

distance speed x time

Question 50

when does diffraction increase

Answer 50

as the gap gets closer to the size of the wavelength

Question 51

LED lights

Answer 51

- stands for “light-emitting diode.” - -- - semi-conductor, which gives off visible light when an electric current flows through it. - used for traffic lights (see Figure below) and also indicator lights on computers, cars, and many other devices. - very reliable and durable.

Question 52

Vapor lights

Answer 52

- produces visible light by electroluminescence - The bulb contains a small amount of solid sodium or mercury as well as a mixture of neon and argon gases. - When an electric current passes through the gases, it causes the solid sodium or mercury to change to a gas and emit visible light. - bright and reliable

Question 53

neon

Answer 53

- A neon light produces visible light by electroluminescence. In this process, neon or some other gas gives off light when an electric current passes through it - When electricity passes through the gas, it excites electrons of neon atoms, and the electrons jump to a higher energy level. As the excited electrons return to their original energy level, they give off visible light.