Science Physics

Question 1

distance

Answer 1

• scalar quantity

- length of space covered between 2 points during an objects motion

Question 2

displacement

Answer 2

• vector quantity
• objects overall change in position
• always measured from the 0 point in metres

Question 3

speed

Answer 3

• scalar quantity
• how fast an object is moving
• rate which an object covers distance

Question 4

velocity

Answer 4

• vector quantity
• rate at which an object changes its position
• does not tell anything about what happens to it between starting point and ending point
• if velocity changes, motion is accelerating.

Question 5

acceleration

Answer 5

• vector quantity
• rate at which an object changes it velocity
• object is accelerating if the velocity is changing
• require an outside force such as gravity
• object with negative acceleration could be speeding up and object with positive acceleration could be slowing down

Question 6

scalars

Answer 6

quantity described by a magnitude only

Question 7

vectors

Answer 7

quantity described by both magnitude and direction

Question 8

newton’s first law

Answer 8

• velocity of an object will remain constant unless acted upon by a net unbalanced force
  example: ball will continue rolling but friction makes it slow down and eventually stop

Question 9

newton’s second law

Answer 9

• net external force acting on a body is directly proportional to and in the same direction as the acceleration of the body
• force = mass x acceleration

example: skydiver jumps from a plane and accelerated until reaching highest velocity point but acceleration is 0. air resistance is equal to downward force of skydiver.

Question 10

newton’s third law

Answer 10

• for every action, there is an opposite and equal reaction

example: presses on wall and wall pushes back for there is an equal and opposite force

Question 11

inertia

Answer 11

• represented by newton’s first law
• object tends to stay at rest or continue motion unless acted by a force
• greater the mass, greater the inertia (harder to stop)

Question 12

physics

Answer 12

• precisely define the most fundamental measurable quantities in the universe
• find relationships between fundamental measured quanities

Question 13

instantaneous speed

Answer 13

-speed of an object at a particular moment in time

magnitudes of the instantaneous speed and velocity are always identical

Question 14

instantaneous velocity

Answer 14

-velocity of an object at a particular moment in time

smaller displacement/ shorter time interval

Question 15

position vs. time graphs

Answer 15

• horizontal line = no motion
• slope = velocity in x direction
• vertical axis = position of object
• slop represents velocity of the object

x2 - x1
———- = slope/velocity
t2 - t1

• if velocity/slope is constant, the acceleration is 0

Question 16

velocity vs. time graphs

Answer 16

• vertical axis = velocity of object
• slope represents acceleration of the object

v2 - v2
———- = slope/acceleration
t2 - t1

• area = displacement
• area under graph represents displacement of the object

Question 17

acceleration vs. time graphs

Answer 17

• vertical axis = acceleration of object
• slope represents quantity called ‘jerk’, rate of change of the acceleration

a2 - a1
———– = slope/ rate of change of acceleration
t2 - t1

• area under graph represents change in velocity
  area = change in velocity
  4V = v - u

Question 18

if acceleration is high

Answer 18

velocity is changing rapidly

Question 19

if acceleration is 0

Answer 19

velocity is exactly constant

Question 20

ticker timer

Answer 20

• machine that makes a series of dots on paper as it moves through the machine
• each length of tape (6 dots) represents 0.1s
  d (length of tape)
  V= —————————
  t (0.1s)
• measures speed and/or acceleration

Question 21

calculate resultant force

Answer 21

add forces acting on an object together (30N + 25N = 55N)

Question 22

acceleration by newton’s equation

Answer 22

a = force/mass

Question 23

momentum

Answer 23

• quantity of motion of a moving body.

momentum (p) = mass x velocity

Question 24

weight

Answer 24

• force of gravity on an objects mass

weight (w) = mass x gravitational acceleration (g)

Question 25

gravity

Answer 25

• point at which whole weight of object appears to act
• sometimes referred to as the center of mass
  m1-m2
  F= G ———–
  (v)^2

gravity on earth = 9.8m/s^2 (x weight of object = Newton weight)

Question 26

mass

Answer 26

the ‘stuff’ or matter made up of in an object

Question 27

newton’s law of gravity

Answer 27

• between 2 objects there is a force of attraction
• greater masses, stronger gravitational force
• distance between masses increases, gravitational force decreases

Question 28

stopping distance of a car - speed at which a car stops is dependent on

Answer 28

• reaction/thinking time
• reaction/thinking distance
• braking distance

Question 29

reaction/ thinking time

Answer 29

time it takes for information to pass from eyes to brain and leg to push the brake

Question 30

reaction/ thinking distance

Answer 30

distance the car travels in the reaction time

Question 31

braking distance

Answer 31

distance car travels between when brakes are applied and when the car stops. dependent on:

• condition of brakes
• condition of tires
• weather conditions
• road conditions

Question 32

total braking distance is measured in

Answer 32

• thinking distance
• braking distance
• total braking distance

Question 33

thinking distance

Answer 33

how FAR the car travels whilst the driver reacts

Question 34

braking distance

Answer 34

DISTANCE TRAVELED after driver puts foot on brake

Question 35

total braking distance

Answer 35

SUM of braking and thinking distance