Section 1 - Motion and Forces

Question 1

What do vector quantities have?

Answer 1

have a magnitude (size) and a direction

Question 2

What are some examples of Vector quantities?

Answer 2

force, velocity, displacement, weight, acceleration & deceleration, momentum

Question 3

What do scalar quantities have?

Answer 3

only have magnitude and no direction

Question 4

What are some examples of scalar quantities?

Answer 4

speed, distance, mass, energy, temperature, time

Question 5

What is distance? And is it a scalar or vector quantity?

Answer 5

Displacement is how far an object has moved
scalar quantity–> no direction

Question 6

What is displacement? And is vector or scalar? explain why?

Answer 6

a measurement of the distance and direction in a straight line from an objects starting point to it’s finishing point
vector quantity–>magnitude & direction

Question 7

What do speed and velocity both measure?

Answer 7

both measures how fast an object is going

Question 8

what is the difference between speed and velocity? And which one is scalar and which one is vector?

Answer 8

speed is how fast your going with no regard to the direction (scalar)
Velocity is speed in a given direction (vector)

Question 9

Give an example of speed and velocity

Answer 9

speed = 30 mph/ 20m/s
velocity = 30 mph north / 20m/s, 060°

Question 10

What happens when an object has a changing direction but stays at the same speed? (scientifically)

Answer 10

the object is travelling at a constant speed with a changing velocity

Question 11

How can you relate the speed and time of an object’s distance travelled through a formula?

Answer 11

distance travelled (m) = (average) speed (m/s) x time (s)

Question 12

What are the typical speeds for walking, running and cycling?

Answer 12

walking = 1.4 m/s (5km/h)
running = 3 m/s (11km/h)
cycling = 5.5 m/s (20km/h)

Question 13

What are the typical speeds for cars in a built-up area and cars on a motorway?

Answer 13

cars in a built-up area = 13m/s (47km/h)
cars on a motorway = 31 m/s (112km/h)

Question 14

What are the typical speeds for aeroplanes, trains and ferries?

Answer 14

aeroplanes = 250 m/s (900 km/h)
trains = 55 m/s (200 km/h)
ferries = 15 m/s (54km/h)

Question 15

What’s the typical wind speed and speed of sound in air?

Answer 15

wind speed = 5-20m/s
speed of sound in air = 340m/s

Question 16

What equipment would you use for measurements of distances less 1m and times greater than 5s? (common measurement done in schools)

Answer 16

stopwatch and metre rulers

Question 17

What equipment is best used to measure distance and time in short time intervals? And why?

Answer 17

light gates
gets rid of human error (caused by reaction times)

Question 18

What is the best equipment used to measure distance and time for measuring a person’s walking speed? And why?

Answer 18

rolling tape measures
optimal for long distances
markers to measure and mark out distances

Question 19

What’s the more expensive high-tech way that can be used to measure distance and time for measuring a object’s walking speed?

Answer 19

calculating the frames per second of an object to find out the distance it has travelled

Question 20

How does the more high tech method to calculating a object’s walking speed work? (give 3 steps)

Answer 20

1)record moving object & look at how far it travels each frame
2) find out how many frames per second were recorded
3)find the distance travelled by object in the frames & time taken

Question 21

what is a physical quantity?

Answer 21

anything that can be measured

Question 22

How can a vector be shown in a drawn description?

Answer 22

drawn as an arrow
length of arrow = magnitude of force

Question 23

What is an arrow that is twice as long as the other trying to represent?

Answer 23

represents a force which has twice the magnitude than the other force

Question 24

what is acceleration?

Answer 24

the change in velocity in a certain amount of time

Question 25

How do you find the average acceleration of an object?
(explain)

Answer 25

a = (v-u)/ t
a = acceleration (m/s^2)
(v-u) = change in velocity (m/s)
v = final velocity (m/s)
u = initial velocity (m/s)
t = time (s)

Question 26

what is initial velocity?

Answer 26

starting velocity of an object

Question 27

What is negative acceleration and what is called (scientifically)?

Answer 27

if an object slows down, the change in velocity is negative (negative acceleration)
deceleration

Question 28

what are the differences of constant and uniform acceleration?

Answer 28

CA-> moving object moves in a direction doesn’t change direction
UA-> moving object covers an equal distance in an equal duration of time

Question 29

What is the similarity between a constant acceleration and uniform acceleration?

Answer 29

the acceleration of an object in constant and uniform acceleration is 0 (no change in velocity)

Question 30

What is uniform acceleration (def.)?

Answer 30

acceleration due to gravity(g) that is uniform for objects in free fall

Question 31

What’s the equation for calculating uniform acceleration?

Answer 31

v^2-u^2 = 2 x A x X
v^2= final velocity (m/s)
u^2 = initial velocity (m/s)
a= acceleration (m/s^2)
x = distance (m)

Question 32

What would happen to two objects that are accelerating due to gravity if other forces such as air resistance didn’t act upon it?

Answer 32

They would accelerate at the same rate if gravity was the only force acting

e.g bowling ball & feather

Question 33

what is the gradient equal to in a distance/time graph?

Answer 33

speed

Question 34

How do you calculate the speed of an object on a straight line in a distance/time graph?

Answer 34

speed = gradient= change in vertical/ change in horizontal

Question 35

What is non-uniform motion?

How do you calculate the average speed of an object when it has non-uniform motion?

Answer 35

acceleration or deceleration
total distance travelled/ time taken to travel distance

Question 36

what is the gradient equal to in a velocity/time graph?

Answer 36

acceleration

Question 37

What does the gradient, flat sections, steeper graph, curves, steeper curves, levelling off curves represent in a distance/time graph?

Answer 37

gradient (slope) at any point = speed of the object
flat section = stopped
steeper graph = going faster
curves = acceleration
curve getting steeper = speeding up (increasing gradient)
levelling off curve = slowing down (decreasing gradient)

Question 38

What does the gradient, flat sections, steeper graph, uphill/downhill sections and curves in a velocity/time graph represent?

Answer 38

gradient = acceleration
flat sections = steady speed
steeper the graph= greater the acceleration/deceleration
uphill sections (/) = acceleration
downhill sections ()= deceleration
curve = changing acceleration

Question 39

What is the gradient equal to in a velocity/time graph? (equation)

Answer 39

gradient = acceleration = change in velocity / time

Question 40

what is the resultant force?

Answer 40

the resultant force is the overall force on a point/object