Physics P3

HideShow resource information
How are x-rays used in hospitals?
To make images and CT scans OR to destroy tumors
1 of 41
What is a disadvantage to x-rays?
Can damage human tissue and cause cancer.
2 of 41
What are x-rays absorbed by?
Bones and teeth
3 of 41
What aren't x-rays absorbed by?
Tissue/skin
4 of 41
What do CT scans distinguish?
Differences between tissue and bone (or teeth).
5 of 41
What frequency are ultrasound above?
20,000HZ
6 of 41
Where are ultrasound waves used in?
Used in medicine for ultrasonic scanning OR destruction of kidney stones.
7 of 41
Why is a ultra sound more safe than a x-ray?
It's non-ionising.
8 of 41
What is reflective index?
Measure of how much a substance can refract a light ray.
9 of 41
What is the algebraic term for refractive index?
n
10 of 41
What's for the formula for n= ?
sin I / sin R
11 of 41
What is the critical angle?
Angle of incidence of a light ray in a transparent substance that produces a refraction above the boundry.
12 of 41
What happens if the critical angle is hit/matched?
Total internal reflection occurs.
13 of 41
What is an endoscope used for?
Used to see inside of the body directly.
14 of 41
When does total internal reflection occur?
When the incidence ray angle in a transparent substance (such as water) is greater than the critical angle.
15 of 41
What does a converging (convex) lens do?
Focuses parallel rays to a point, called the principal focus.
16 of 41
What does a diverging (concave) lens do?
Makes parallel rays spread out as if they come from the principal focus point.
17 of 41
What type of image is formed by a converging (convex) lens?
'Real image' if the object is further away than the principal focus, then too by a convex lense.
18 of 41
What type of image is formed by a diverging (concave) lens?
'Virtual image' and if the object nearer to the lense than the principal focus, it's also produced by a converging lens.
19 of 41
What's the equation for magnification?
image height/object height
20 of 41
What type of lens does a camera contain and what type of image is produced?
Converging lens that's used to form a real image of an object.
21 of 41
What type of lens is a magnifying lens and what type of image is formed?
Converging lens which forms a virtual image.
22 of 41
What is light focused by in the eye?
Onto the retina by the cornea and eye lens.
23 of 41
What's the range of human eye?
25cm to infinity and beyond.
24 of 41
How does refractive index influence how thick/thin a lens can be?
The higher the refractive index, the flatter and thinner it can be.
25 of 41
What is the moment of a force?
A measure of the turning effect of the force on an object.
26 of 41
What is the centre of mass of an object?
Where an object's mass may thought to be concentrated and balanced.
27 of 41
What happens when a suspended object is in equilibrium?
Centre of mass is directly below the point of suspension.
28 of 41
How can we find the centre of mass of an object?
A plumb line
29 of 41
How can you make a object more stable?
Make it heavier, or have a wider base (such as on a tractor).
30 of 41
For an object in equilibrium, the sum of anti clock moments = ?
= the sum of clockwise moments around that point.
31 of 41
What would cause a object to topple?
If the line of action/centre of mass is outside the base.
32 of 41
The pressure of a hydraulic fluid is?
Acts equally in all directions so equal/the same.
33 of 41
What does a hydraulic system use?
Pressure in a fluid to exert a force.
34 of 41
Pressure = ? / ?
force / area
35 of 41
What is the unit of pressure?
Pascal (PA) which is equal to 1N/m(2)
36 of 41
Why is the velocity of a object moving in a circle constantly changing?
The object is constantly changing direction so as is it's velocity.
37 of 41
What is centripetal acceleration?
The acceleration towards the centre of the circle of an object moving around the circle.
38 of 41
What does the centripetal force of an object depend on? Give 3 answers.
It's mass, speed and radius of the circle.
39 of 41
What does the time period of a simple pendulum depend on?
It's length.
40 of 41
How can you workout the time period of the pendulum?
Measure the average time for 20 oscillations and / by 20.
41 of 41

Other cards in this set

Card 2

Front

What is a disadvantage to x-rays?

Back

Can damage human tissue and cause cancer.

Card 3

Front

What are x-rays absorbed by?

Back

Preview of the front of card 3

Card 4

Front

What aren't x-rays absorbed by?

Back

Preview of the front of card 4

Card 5

Front

What do CT scans distinguish?

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Physics resources:

See all Physics resources »See all Energy resources »