motions and forces

what is scalar quantity?

scalar quantities have a _____ or ______ but _____ specific direction

scalar quantities have a size or magnitude but no specific direction

what is a vector quantity?

vector quantities have a _____ or ______ but _____ specific direction

vector quantities have a size or magnitude but with specific direction

whats the difference between speed and velocity?
velocity is speed but with a ________.

velocity is speed but with a direction.

what is speed?

speed is the _____ that a moving object ____ every second.

speed is the distance that a moving object covers every second.

what does the gradient / slope tells us in a distance time graph?

the gradient / slope tells us about the ______ of the vehicle.

the gradient / slope tells us about the motion of the vehicle.

what motion is this?

stationary

what motion is this?

constant / steady

what motion is this?

accelerating

what motion is this?

decelerating

what is acceleration?

the change in ______ per second

the change in velocity per second

what is velocity?

the change in _______ _______ per second

the change in distance travelled per second

how do you calculate the acceleration and distance in a velocity / time graph?

1. find the acceleration by doing change in _____ divided by _____

2. find distance by working out the ____ of the graph (velocity times time)

1. find the acceleration by doing change in _____ divided by _____

2. find distance by working out the ____ of the graph (velocity times time)

determining speed practical.

1. put a specific ______ and attach _____ onto the trolley

2. measure the ______ of the card attached to the trolley using a _____ ruler

3. position two l____ ____ along at the ramp at a _____ distance apart

4. put specific mass onto ______ hanger

5. release the trolley from a ______ position at the top of ramp from _____

6. as the trolley passes through the light gate, the light gates measure the ______ taken for the card to ______ the light ______

7. calculate speed using equation: speed = ______/____

1. put a specific mass and attach card onto the trolley

2. measure the length of the card attached to the trolley using a metre ruler

3. position two light gates along at the ramp at a measured distance apart

4. put specific mass onto weight hanger

5. release the trolley from a fixed position at the top of ramp from rest

6. as the trolley passes through the light gate, the light gates measure the time taken for the card to interrupt the light beam

7. calculate speed using equation: speed = distance/time

what are the different variables of this practical?

independent: _____ of trolley or ____ of ramp or _____ traveled

dependent: ____ taken for the light beams to be _______

control: _____ position of trolley, ____ of trolley, slope _____

independent: mass of trolley or height of ramp or distance travelled

dependent: time taken for the light beams to be interrupted

control: starting position of trolley, mass of trolley, slope angle

what is newtons first law?

a body will remain _____ or continue in a _____ line at a ____ speed as long as the _____ acting on it are _____.

a boy will remain stationary or continue in a straight line at a constant speed as long as the forces acting on it are balanced.

newtons first law simply states that:

when the resultant force is 0:

• if the object is stationary, it _____ __ _____

• if the object is moving, it continues to move at a _____ speed in a _____ line.

when the resultant force is 0:

• if the object is stationary, it stays at rest

• if the object is moving, it continues to move at a constant speed in a straight line.

newton’s first law simply states that:

when the resultant force is NOT 0:

if there’s an ______ resultant force acting on an object, it’s _____ will change, meaning it’ll ________ in the _______ of resultant force.

when the resultant force is NOT 0:

if there’s an unbalanced resultant force acting on an object, it’s velocity will change, meaning it’ll accelerate in the direction of resultant force.

an unbalanced resultant force can cause an object to: (3 points)

speed up

slow down

change direction

what is newton’s second law?

when a _____ ____ act on a mass, then there will be a ______ in it’s velocity.

in plain English: if the force acting on an object doesn’t cancel out to _____, it can’t stay at a ____ speed in a _____ line. it MUST change it’s _____ or _____.

when a resultant force act on a mass, then there will be a change in it’s velocity.

in plain English: if the force acting on an object doesn’t cancel out to zero, it can’t stay at a constant speed in a straight line. it MUST change it’s speed or direction.

newton’s second law also states that:
the resultant force determines the ____ and ____ of the subquent ______ of the mass.

the resultant force determines the size and direction of the subquent acceleration of the mass.

in simple terms, the second thing the newton’s second law states that:

for size (how big the acceleration is):

a bigger _____ ____ = bigger ______

a bigger _____ = ______ acceleration

for direction (where acceleration travels towards):

object acceleration is in direction of ____ _____

for size (how big the acceleration is):

a bigger resultant force = bigger acceleration

a bigger mass = smaller acceleration

for direction (where acceleration travels towards):

object acceleration is in direction of resultant force

what is inertial mass?

inertial mass is a measure of how _____ it is to change the ____ of a _____ object and is defined as the ratio ‘force over ______’

inertial mass is a measure of how difficult it is to change the velocity of a moving object and is defined as the ratio ‘force over acceleration’

what is weight?

the ____ that a body experiences due to it’s mass and size of the _________ _____ its in.

_____ quantity measured in newtons.

weight on body on surface of earth acts ____ to earth’s centre.

the force that a body experiences due to it’s mass and size of the gravitational field its in.

vector quantity measured in newtons.

weight on body on surface of earth acts inwards to earth’s centre.

what is mass?

a measure of the amount of _____ that’s contained within a 3D _____.

____ quantity measured in kilograms.

______ of body’s not affected by the gravitational field it’s in.

a measure of the amount of matter that’s contained within a 3D space.

scalar quantity measured in kilograms.

mass of body’s not affected by the gravitational field it’s in.

the gravitational field strength of a body, such as a planet depends on it’s:

• _____ of body

• _____ of body

when a body has a _____ mass and a ____ radius, it’s have a larger gravitational field strength, hence why heavier objects falls faster.

mass of body

radius of body

when a body has a larger mass and a smaller radius, it’s have a larger gravitational field strength, hence why heavier objects falls faster.

weight is measured by using a?

newtonmeter

the greater the _____ attached, the more ____ it will experience due to gravity, and the more the spring will _____.

the greater the mass attached, the more weight it will experience due to gravity, and the more the spring will stretch.

a body moving in a circular path with _____ speed still has a _____ velocity. this is because velocity’s a _____ quantity meaning it contains both size and direction so since it’s _____ is changing, the velocity changes too.

a body moving in a circular path with constant speed still has a changing velocity. this is because velocity’s a vector quantity meaning it contains both size and direction so since it’s direction is changing, the velocity changes too.

for circular motion to occur, there must be a _____ acting _____ along the radius of the circle. this is called the ______ force. the object moves at ____ angles to this force.

for circular motion to occur, there must be a force acting inwards along the radius of the circle. this is called the centripetal force. the object moves at right angles to this force.

if there’s no forces acting on the satellite, it would move in a ____ ____.

the gravitational force acting towards the earth acts on the satellite. this is called the ______ ____, and acts at ____ degrees to the direction of motion of satellite.

speed of satellite remains ____, but the ____ constantly changes due to change in _____. this means that the satellite is _______ even though it’s traveling at a constant speed.

if there’s no forces acting on the satellite, it would move in a straight line.

the gravitational force acting towards the earth acts on the satellite. this is called the centripetal force, and acts at 90 degrees to the direction of motion of satellite.

speed of satellite remains constant, but the velocity constantly changes due to change in direction. this means that the satellite is accelerating even though it’s traveling at a constant speed.

what is centripetal force?

a force acting _____ along the ____ of the circle.

a force acting inwards along the radius of the circle.

four main types of centripetal force that results in circular motion.

gravitational

frictional

tension

electrostatic

the momentum of a moving object depends on its ____ and ____.

the momentum of a moving object depends on its mass and velocity.

force is the rate of change of _____.

force is the rate of change of momentum.

since force is directly proportional to both ______ and change of ______, when the mass or deceleration of a vehicle are large, the _____ exerted on the passengers are also large.

since force is directly proportional to both masses and change of momentum, when the mass or deceleration of a vehicle are large, the force exerted on the passengers are also large.

larger mass = larger _______ required for the vehicle to stop.

because to stop a ____ object over the same duration requires a much larger ____ to be exerted on the vehicle and passengers.

larger mass = larger momentum required for the vehicle to stop.

because to stop a heavier object over the same duration requires a much larger force to be exerted on the vehicle and passengers.

larger ______ = larger force

because when a vehicle stops ______ (meaning large deceleration), the time taken for the vehicle to stop ______ dramatically.

so when you divide change in _____ by a smaller time, the resulting impact force becomes _____.

larger deceleration = larger force

because when a vehicle stops suddenly (meaning large deceleration), the time taken for the vehicle to stop decreases dramatically.

so when you divide change in momentum by a smaller time, the resulting impact force becomes massive.

how does car safety features such as seat belt reduce size of forces exerted on passengers and drivers?

because it _______ the time over which the vehicle _____ __ _____.

because it increases the time over which the vehicle comes to rest.

newton’s third law states that:
for every action, there’s an _____ and _____ reaction. the _____ force and the ______ force acts on different _____.

for every action, there’s an _____ and _____ reaction. the _____ force and the ______ force acts on different _____.

the man and the wall are in ______ because the forces in the system are all ______.

there’s no overall _____ in any direction.

the man and the wall are in equilibrium because the forces in the system are all balanced.

there’s no overall force in any direction.

just because two forces are equal and opposite, it doesn’t always mean that they’re an example of newton’s third law.

for example:

the _____ force of the table pushing up on the book, and the force of ______ acting downwards are both acting on the _____ object, so it’s not an example of newton’s third law.

the reaction force of the table pushing up on the book, and the force of gravity acting downwards are both acting on the same object, so it’s not an example of newton’s third law.

when the truck and car collide, they exert ____ and _____ forces on each other and are in contact for the same amount of ____.

_______’s therefore conserved.

when the truck and car collide, they exert equal and opposite forces on each other and are in contact for the same amount of time.

momentum’s therefore conserved.