Acceleration and Equations of Motion

Question 1

acceleration

Answer 1

change of velocity per unit time

Question 2

acceleration equation

Answer 2

(v-u)/t

Question 3

What is a method of measuring acceleration?

Answer 3

single card 2 light gates computer measure velocity of each light gate and time between

Question 4

measuring distance travelled on graph

Answer 4

total area under speed-time graph

Question 5

measuring displacement on graph

Answer 5

total area under velocity-time graph

Question 6

Describe this velocity-time graph.

Answer 6

accelerates for 10min constant velocity of 60m/min for 5min decelerates for 15 mins accelerates for 10 mins in opposite direction decelerates for 15 mins

Question 7

derive v = u + at

Answer 7

• a = (v-u)/t
• v = u + at

Question 8

derive s = ut + ½at²

Answer 8

• s = vt
• replace v with average velocity s = ((u+v)/2)t
• subsititue in v = u + at
• s = ½(u + (u + at))t
• s = ½(2u + at)²
• s = ½(2ut + at²)
• s = ut + ½at²

Question 9

derive v² = u² + 2as

Answer 9

• v = u + at
• t = (v – u)/a
• s = ½(u + v)((v – u)/a)
• s = ((v + u)(v – u))/2a
• 2as = (v + u)(v – u)
• 2as = v² – u² v² = u² + 2as

Question 10

derive s = ½(u + v)t

Answer 10

• average velocity = (u + v)/2
• s = ((u + v)/2)t
• s = ½(u + v)t

Question 11

deceleration

Answer 11

acceleration decreases (negative acceleration)

Question 12

any object freely moving through the air is… towards the ground under the influence of…

Answer 12

accelerated gravity

Question 13

what does gravity provide?

Answer 13

doward acceleration of 9.81m/s^2

Question 14

what happens the instant an object is dropped?

Answer 14

stationary so u = 0m/s

Question 15

what is the accleration of a dropped object?

Answer 15

-9.8m/s^2

Question 16

what is the initial velocity of an object launched upwards?

Answer 16

u = maximum upward velocity

Question 17

what happens when an object reaches its maximum height?

Answer 17

v = 0m/s

Question 18

projectile

Answer 18

any object that is thrown, launched or falls through air

Question 19

trajectory

Answer 19

path travelled by projectile

Question 20

what effect does air resistance have on values obtained in experiments involving projectiles?

Answer 20

slightly lesser

Question 21

horizontal projectiles horizontal velocity

Answer 21

remains constant until hits the ground

Question 22

horizontal projectiles the larger the horizontal component, the … the range

Answer 22

larger

Question 23

horizontal projectiles horizontal acceleration

Answer 23

no acceleration

Question 24

horizontal projectiles horizontal displacement equation

Answer 24

horizontal velocity x time

Question 25

horizonal projectiles vertical initial velocity

Answer 25

u = 0m/s

Question 26

horizontal projectiles vertical acceleration

Answer 26

gravity

Question 27

horizontal projectiles the greater the initial vertical velocity the ... the final velocity just before hitting the ground

Answer 27

greater

Question 28

what shape does a projectile fired from ground have?

Answer 28

symmetrical parabolic trajectory

Question 29

range

Answer 29

horizontal distance travelled

Question 30

when does the projectile reach its maximum height?

Answer 30

half its range half time taken to complete journey

Question 31

how to split projectile motion into horizontal and vertical components?

Answer 31

vertical = usinO horizontal = ucosO

Question 32

what remains constant during projectile motion?

Answer 32

horizontal component

Question 33

how to graph the vertical component of velocity?

Answer 33

Question 34

How does horizontal motion show that air resistance is negligible?

Answer 34

displacement constant therefore velocity constant no acting horizontal force

Question 35

How to explain vertical motion of projected object?

Answer 35

object accelerates due to gravity constant acceleration

Question 36

If air resistance is not negligible what effect does this have on... 1. horizontal motion? 2. vertical motion?

Answer 36

1. horizontal displacement less 2. accelerates less vertically * effect of air resistance increases with time * reaches terminal velocity

Question 37

Why is horizontal motion constant?

Answer 37

no horizontal force therefore no horizontal acceleration

Question 38

Why does acceleration decrease down a ramp?

Answer 38

component of weight down slope causes acceleration component decreases as moves down slope air resistance and friction increase with speed