Mechanics and waves

Question 1

What is the centre of gravity

Answer 1

A point on the object where gravity appears to act generally in the middle but not always

Question 2

Why is a tall glass easily toppled

Answer 2

It is easily toppled when the line of action of its weight is beyond the edge of the base then the glass tips right over

Question 3

Definition of moment

Answer 3

The product of the force * the perpendicular distance from the pivot

Question 4

What is the eqaution for moments

Answer 4

Moments = FD

Question 5

What is the pivot point

Answer 5

The point of Whitchurch an object rotates about

Question 6

How do you know when an object is equilibrium

Answer 6

When the sum of clockwise moments equals the sum of anti-clockwise moments and there is no resultant force

Question 7

How would you calculate the centre of mass of a piece of card

Answer 7

Hang up the card and suspend a plumb line from the same place
Mark the position of the thread
Repeat the above steps with the card suspended from different places
Where these lines intersect is the centre of mass

Question 8

Definition of equilibrium

Answer 8

No resultant force
No resultant moment

Question 9

What is the eqaution for momentum

Answer 9

P = mass * velocity

Question 10

How do you work out velocity.

Answer 10

Total distance / total time

Question 11

How do you work out GPE

Answer 11

GPE = MGH

Question 12

How do you work out Ke

Answer 12

1/2 Mvsqaured

Question 13

What is a scalar measurement

Answer 13

An amount just with a magnitude
Energy work done
Distance around a circle

Question 14

What is vector measurement

Answer 14

An amount with a direction
Distance you are form the start of circle

Question 15

What is an example of a scalar measurement

Answer 15

Speed

Question 16

What are examples of vector measurements

Answer 16

Displacement
Force
velocity
Acceleration

Question 17

What is the change in momentum also called

Answer 17

An impulse

Question 18

How can you calculate F

Answer 18

F= impulse/time

Question 19

What is the equation for momentum

Answer 19

Mass * velocity

Question 20

What are the three conservation laws

Answer 20

Conservation of energy
Conservation of moments in equilibrium
Conservation of momentum

Question 21

What does the conservation of energy state

Answer 21

The total energy after something happens is equal to the total energy before something happens

Question 22

What does the conservation of moments in equilibrium state

Answer 22

Anti-clockwise moments are equal to clockwise moments

Question 23

What does the conservation of momentum state

Answer 23

The total momentum before something is happening is eqaul to the total momentum of something after it happens

Question 24

How do you calculate the distance from a graph

Answer 24

Area under the graph

Question 25

What is the spring extension in terms of measured length and original lengthe

Answer 25

Measured length - original length

Question 26

How do you know when an object is in equilibrium

Answer 26

If it’s centre of mass is vertically above the pivot point

Question 27

Definition of equilibrium

Answer 27

Resultant force on something is zero and the resultant, turning affect on something is zero

Question 28

What happens to the acceleration of a stone when it falls

Answer 28

Celebration stays the same never increasing or decreasing the velocity increases while gravity is 9.8

Question 29

Definition of amplitude

Answer 29

From the average position of the crest or distance, measured from average position to the trough

Question 30

Definition of wavelength

Answer 30

The distance between two corresponding points on the wave and is measured in metres

Question 31

Definition of frequency

Answer 31

This is how many waves pass by every second and is measured in hertz

Question 32

Definition of transverse waves

Answer 32

When the displacement is it, a right angle to the direction of the wave is energy travelling

Question 33

Definition of longitude waves

Answer 33

When the displacement is parallel to the direction of the wave

Question 34

How do you calculate the wave velocity?

Answer 34

Frequency * wavelength

Question 35

What are wave describes as around a fixed point?

Answer 35

Oscillation and vibration

Question 36

What are examples of oscillation and vibration Waze?

Answer 36

Ripples cause particles of water to oscillate up and down sound waves cause particles of a to vibrate back and forth

Question 37

The toy dog bobbing up and down on top of the surface of some water as waves pass it underneath, explain how the toy dog demonstrates that we do not transfer matter

Answer 37

Step one identified the wave. The type of wave on the surface of a body of water is a transverse wave, because the duck is moving perpendicular to the direction of the wave step to describe the motion of the toy doc, the plastic duck moves up and down, but does not travel with the wave step three explain how this motion demonstrates the waves do not transfer matter both transverse and longitudinal waves transfer energy but not the particles of the medium. This means when a wave travels between two points no matter actually travels with it the points on the way you just vibrate back-and-forth about fix positions objects floating on the water that simply pop up and down when the waves pass underneath them, demonstrating that there is no movement of matter in the direction of the wave only energy.

Question 38

What is the definition of defimition

Answer 38

When the displacement is it, a right angle to the direction of the waves energy travelling

Question 39

What is three processes of waves when they interact with other objects

Answer 39

Reflection, refraction diffraction

Question 40

What is the law of reflection?

Answer 40

The angle of incidence equals the angle of reflection

Question 41

How do you find the angle of incidence?

Answer 41

Always measured from the ray to the normal

Question 42

How do you mark the normal?

Answer 42

It is always at a right angle to the boundary

Question 43

In refraction flight goes on from the normal what happens to it?

Answer 43

It’s slows down then speeds up, but doesn’t bend because doesn’t go in at an angle

Question 44

What happen when waves across a Boundry and slow down

Answer 44

Play Ben towards does a normal

Question 45

What happens to the beam after the change in angle from a refraction?

Answer 45

the frequency stays the same wavelength before is bigger than the wavelength after the velocity before is greater than the velocity after

Question 46

What is a medium?

Answer 46

Something the waves will travel through

Question 47

What is the difraction?

Answer 47

Maximum the fraction is the weather like disperses greatly after going through a gap in the wall. If the gap is small, you get maximum diffraction, but if the gap is big, you get minimum diffraction