# Topic 2.1-Motion Flashcards Preview

## *Edexcel A-Level Physics* > Topic 2.1-Motion > Flashcards

Flashcards in Topic 2.1-Motion Deck (44)
1
Q

Define speed

A

The rate of change of distance with time

3
Q

What is the equation for speed?

A

Speed=distance/time ms-1

4
Q

Define velocity

A

The rate of change of displacement with time, where displacement is a distance in a stated direction

5
Q

What is the equation for velocity?

A

Velocity= displacement/time ms-1 plus direction v= Δs/Δt

6
Q

Are displacement and velocity scalar or vector quantities?

A

Vector; magnitude and direction

7
Q

How can you find instantaneous velocity graphically?

A

Draw a tangent at a point and work out the gradient using Δy/Δx

8
Q

Define acceleration

A

The rate of change of velocity with time

9
Q

What is the equation for acceleration?

A

Acceleration= change in velocity/time ms-2 plus direction a= Δv/Δt OR a= v-u/t

10
Q

What could a negative acceleration mean?

A

1) Accelerating backwards (against original direction) 2) Deceleration

11
Q

How can average acceleration be measured using lab techniques?

A

Roll a trolley with a interrupter card attached down a ramp, through two separate light gates attached to a data logger. Distance= length of card Time= time in each data logger Calculate the velocity at each light gate then work out acceleration using a=v-u/t TAKE REPEAT READINGS!

12
Q

How can instantaneous acceleration be calculated using lab techniques?

A

Roll a trolley with a picket fence interrupter card attached down a ramp, through a light gate attached to a data logger. Distance= length of each ‘picket’ on the card Time= time in each data logger Calculate the velocity at each light gate then work out acceleration using a= Δv/t TAKE REPEAT READINGS!

13
Q

What are the benefits of using data loggers to record data?

A

-Synchronous readings -Recordings as exact times -Higher sampling rate -Fewer people needed to complete investigation -Less chance of random error (due to to human reaction time)

14
Q

Why is random error harder to be accounted for than systematic error.

A

It is different every time

15
Q

What are kinematic equations?

A

Equations used for any object that is accelerating

16
Q

What does SUVAT stand for?

A

S-displacement (m)

U-initial velocity (ms-1)

V-final velocity (ms-1)

A-acceleration (ms-2)

T-time (s)

17
Q

What is the SUVAT equation for final velocity? How is it derived?

A

V=u+at a= Δv/t ➡️ a=v-u/t ➡️ at=v-u ➡️ v=u+at

18
Q

What is the SUVAT equation for displacement when you have final velocity? How is it derived?

A

s=(v+u/2)t average velocity=(v+u/2) and s=dt ➡️(substitution)➡️ s=(v+u/2)t

19
Q

What is the SUVAT equation for displacement when you don’t have final velocity? How is it derived?

A

s=ut+1/2at2 s=(v+u/2)t and v=u+at ➡️(substitution)➡️ s=(u+at+u/2)t ➡️ s=t(2u/2 +at/2) ➡️(expansion)➡️ s=ut+q/2at2

20
Q

What is the SUVAT equation for velocity^2? How is it derived?

A

V2=u2+2as V=u+at ➡️ v2=(u+at)2 ➡️(expand)➡️ v2=(u+at)(u+at) ➡️ v2=u2+2uat+a2t2 ➡️(factorise)➡️ v2=u2+2a(ut+1/2at2) and s=ut+1/2at2 ➡️(substitution)➡️ v2=u2+as

21
Q

Name 3 types of motion graphs

A

Distance-time Velocity-time Acceleration-time

22
Q

What is the gradient for a distance-time graph?

A

Velocity= Δs/t

23
Q

What is the gradient for a velocity-time graph?

A

Acceleration= Δv/t

24
Q

What does the area under a velocity-time graph represent?

A

Distance

25
Q

What are 3 ways which you can measure ‘g’ by free fall?

A

-electromagnet/trap door method -light gate method (picket fence is dropped) -multiflash photography

26
Q

Is speed a scalar or vector quantity?

A

Scalar; it has magnitude only

27
Q

How are vectors added in line?

A

Add same direction and subtract oposite direction

28
Q

How do you add perpendicular vestors?

A

Draw a free body diagram and se Pythagoras’ theorem or trigonometry.

29
Q

How do you add oblique vectors?

A

Draw a scale diagram (a parallelogram to find the hypotenuse length).

30
Q

What is a free-body diagram?

A

A diagram with the object drawn and the forces drawn on.

31
Q

Define a moment:

A

A measure of an objects tendency to cause rotation.

32
Q

What is the equation for a moment?

A

Moment= Force x Perpendicular distance from pivot to line of action

M (Nm)= F(N) d (m)

33
Q

Describe an object in rotational equilibrium:

A

The resultant force acting of it is zero. This is known as the principle of moments which means that the clockwise moment= anticlockwise moment.

34
Q

Define centre of gravity:

A

The position where the sum of an objects weight force appears to act from.

35
Q

How is centre of gravity found for symmetrical objects?

A

At the intersection of lines of symmetry.

36
Q

How is centre of gravity found for irregular objects?

A

Hanging an objects with a plumbob and drawing lines as it falls.

37
Q

What is Newton’s first law?

A

If an object is stationary it will stay stationary unless acted on by a resultant force.

If an object is moving at a constant velocity it will stay at that velocity unless acted on by a resultant force.

38
Q

What is Newton’s second law?

A

Resultant force= mass x acceleration

F (N) = m (kg) a (ms-1)

39
Q

What is Newton’s third law?

A

To every action there is an equal and opposite reaction.

40
Q

What are 5 differences between Newton’s first and third laws?

A

1) Forces in Newton I acts on a single object while forces in Newton III act of 2 different objects.
2) Newton I concerns any number of forces while Newton III always concerns only 2.
3) The forces can be different types in Newton I while they must be the same in Newton III.
4) Forces are always equal and opposite in Newton III but they must be two forces on a body in equilibrium for this to occur in Newton I
5) Newton III always applies but Newton I only appies for bodies in equilibrium.

41
Q

What are the 4 kinds of forces?

A

Electromagentism

Gravity/ gravitational

Strong force

Subatomic weak force

42
Q

Define projectile:

A

A moving object on which the only force of significance acting on it is weight. They are generally thrown and form a pre-determined trajectory based on its initial velocity

43
Q

What 3 kinds of projectile are there?

A

Vertical

Horizontal

Oblique

44
Q

What shape does a horizontal projectile form?

A

A parabola

45
Q

How does speed change for horizontal and vertical components of projectiles?

A

Horizonal projectiles: constant velocity s=vt

Vertical projectiles: accelerating at ‘g’ SUVAT equations