3 - Motion Flashcards Preview

A level physics Flashies > 3 - Motion > Flashcards

Flashcards in 3 - Motion Deck (24)
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1
Q

What is average speed?

A

The average speed of an object over the entire course of its journey.

2
Q

What is instantaneous speed?

A

The speed of an object over a very short interval of time.

3
Q

What does the gradient of a straight distance time graph represent?

A

The average speed.

4
Q

How do you find the instantaneous speed at a certain time from a distance time graph?

A

Draw a tangent to the line at that time and find the gradient of the tangent.

5
Q

How do you find the top instantaneous speed from a distance time graph?

A

Draw a tangent at the steepest point of the graph and find the gradient.

6
Q

Define acceleration.

A

The rate of change in velocity.

7
Q

What is the difference between speed and velocity?

A

Speed is a scalar and velocity is a vector.

8
Q

What is acceleration, a scalar or a vector?

A

Vector (determined from velocity)

9
Q

What does the gradient of a velocity time graph represent?

A

Acceleration

10
Q

What are all of the suvat equations?

A

v =u + at
s = ut + 1/2at^2
s = (v+u)/2 x t
v^2 = u^ + at

11
Q

What is thinking distance?

A

The distance traveled in the time between the driver realising that they have to stop, and starting to brake.

12
Q

What is braking distance?

A

The distance travelled in the time from when the brake is pressed to when the vehicle stops.

13
Q

What is stopping distance?

A

Thinking distance + breaking distance

14
Q

How do you calculate thinking distance?

A

speed x reaction time

15
Q

What factors affect thinking distance?

A
  • Tiredness
  • Alcohol/depressants
  • Distractions
  • Speed of the car
  • Age
  • Stimulants
16
Q

What factors affect stopping distance?

A
  • Tyre condition
  • Road condition
  • Weather
  • Brake condition
  • Mass of the car
  • Speed of the car
17
Q

What do all objects with a mass exert?

A

A gravitational pull on other massive objects around them.

18
Q

What does massive mean?

A

An object as a mass.

19
Q

What is gravitational field strength?

A

The acceleration that an object experiences due to gravity.

20
Q

What is the gravitational field strength close to the surface of the earth?

A

9.81m/s

21
Q

What must you always remember when calculating projectile motion?

A

Horizontal and vertical projectile motions are independent of each other.

22
Q

What steps must you follow when calculating projectile motion?

A
  1. Sketch and label everything
  2. Split magnitude of velocity into vertical and horizontal components using trigonometry
  3. Work out missing suvat values for each component
23
Q

What is the relationship between braking distance and velocity?

A

Distance ∝ velocity^2

24
Q

What is the relationship between braking distance and mass?

A

Distance ∝ mass