Flashcards in Chapter 3, Motion Deck (17):

1

## Defining equation for speed?

### v=x/t (speed = change in distance/change in time).

2

## Which axis is which on a distance-time graph?

### time is x-axis, distance is y-axis.

3

## What is given by the gradient of a displacement-time graph?

### Velocity.

4

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

### Draw a tangent.

5

## What are the vector quantities of distance and speed?

### Displacement and velocity.

6

## Defining equation for acceleration?

### a=v/t (change in velocity/change in time).

7

## How do you find the total displacement from a velocity-time graph?

### Find the area under the curve.

8

## What do the letters in the suvat equations represent?

### s=displacement, u=initial velocity, v=final velocity, a=acceleration, t=time taken.

9

## Suvat equation including a,v,u and t?

### a=(v-u)/t, derived from defining equation for acceleration

10

## Suvat equation including s,u,a and t?

### s=ut+(1/2)at^2, from area of trapezium from velocity-time graph. Also s=vt-(1/2)at^2 is also a valid equation.

11

## Requirements for suvat equations to apply?

### Acceleration is constant for motion in a straight line.

12

## Suvat equation including s,u,v and t?

### s=(1/2)(u+v)t from the average velocity * time.

13

## Suvat equation including s,u,v and a?

### v^2=u^2-2as.

14

## What factors affect stopping distance?

### Thinking distance and breaking distance.

15

## How do you calculate thinking distance when stopping a car?

### Thinking distance = speed*reaction time

16

## What methods are there for determining acceleration due to gravity (g)?

###
Electromagnet and trapdoor:

An electromagnet holds a steel ball above a trapdoor, when the current is switched off the ball falls breaking the contact in the trapdoor stopping the timer.

Light gates:

Use two sets of double light gates to determine change in velocity

Taking pictures:

By taking pictures of a falling object at small regular intervals you can measure how much more the ball falls each time and use this to measure g.

17