QUESTIONS

ANSWER BOX

1.

How do your eyes change when you go from a light to dark room?

Your pupils get larger.                                        

2.

Explain how you can see this page.

Light rays are reflected from the page into my eye. The rays are focused to an image on my retina, and then signals are sent to my brain through the optic nerve.

3.

State the Law of Reflection.

The angle of incidence always equals the angle of reflection.

4.

An object is placed 10 cm in front of a mirror. Where does the image appear to be?

10 cm behind the mirror.                                        

5.

What are the two types of curved mirror called?

Convex and concave mirrors.

6.

What is an inverted image?

An upside-down image.                                        

7.

How can you make the image in a pinhole camera larger?

Make the pinhole larger.                                        

8.

What is the disadvantage of making the image brighter in the pinhole camera?

The image gets blurred as the hole gets larger.

9.

All sounds are made by v___________ and they travel through the air as w___________

vibrations, waves.                                                                 

10.

Why do you see a lightening flash before you hear the thunder?

Light travels faster than sound

11.

Why do we hear echoes?

Because sound is reflected off objects.

12.

What do we call sound that is too high for us to hear?

Ultrasonic sound (ultrasound).

13.

What part of your ear vibrates when sound enters it?

The ear drum.                                         

14.

How many small bones are there in the car?

3.                                                                                 

15.

What is the name of the spiral containing liquid in the inner ear?

The cochlea                                        

16.

How can listening to loud music in a disco damage your ear?

Loud music can cause your ear drum to rupture (puncture).

17.

If sound can travel 990 metres in 3 seconds, what is the speed of sound?

330 metres per second

18.

Which medium does sound travel fastest through, air, water, vacuum or rock?

Rock