Text P409-413. Mass and Inertia The universe consists of matter in motion The universe consists of...
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Text P409-413
Transcript of Text P409-413. Mass and Inertia The universe consists of matter in motion The universe consists of...
Text P409-413
Mass and Inertia
The universe consists of matter in motion
The universe consists of matter in motion
The greater the mass the harder it is to move. And . . .the harder it is to stop moving.
The greater the mass the harder it is to move. And . . .the harder it is to stop moving.
Lower mass objects are easier to move . . .and to stop moving.
NEWTON’s Laws 1st Law of Motion :
NEWTON’s Laws 1st Law of Motion :
An object remains at a
in a ,until a net force acts on it.
An object remains at a
in a ,until a net force acts on it.
constant speed straight pathconstant speed straight path
An object willremain at a
constant speed (unless
disturbed).
NEWTON’s 1st Law of Motion is the law of
Higher mass higher momentumHigher velocity higher momentum
Momentum = mass x velocity
includes velocity. So, it has direction. Momentum points in the direction of motion.
Conservation of momentumWhen objects collide, all of the momentum goes somewhere.
Conservation of momentumWhen objects collide, all of the momentum goes somewhere.
Conservation of momentumWhen objects collide, all of the momentum goes somewhere.
Conservation of momentumWhen objects collide, all of the momentum goes somewhere.
NEWTON’s2nd Law of Motion :
An object that
has a force acting on it will change its speed (accelerate).
Net force is the total amount of Force (minus the forces that cancel each other out). Force of gravity
Force of muscles
Net force
When the net force is Zero.-> NO movement
When the net force is NOT Zero.-> movement
When the net force is Zero.-> NO movement
When the net force is NOT Zero.-> movement
2 Kg ?
Static Equilibrium Balanced forces
When all forces are balanced. The net force is Zero. There is NO movement.
Static Equilibrium Balanced forces
When all forces are balanced. The net force is Zero. There is NO movement.
3 Kg
50 N
100 N
100
N50 N
50 N
50 N
NEWTON’s 3rd Law of Motion:
For every action there is an equal and opposite reaction.
NEWTON’s 3rd Law of Motion:
For every action, there is an equal and opposite reaction.
NEWTON’s 3rd Law of Motion:
For every action, there is an equal and opposite reaction.
Balanced or unbalanced?Action
Reaction
Gravity Inertia FrictionGravity Inertia Friction
A car is traveling down a hill. Which of the following will affect the amount of energy the car has?
how long the car is
the time of day
how much the car weighs
the color of the car
Friction the resistive force that occurs
when two surfaces travel past each other.
causes physical deformationgenerates heat
Friction the resistive
force that occurs when two surfaces contact each other.
Oliver the dog doesn't want to walk in the rain. He can make his owner pull harder on the leash to
get him out the door by
sitting on the vinyl floor. sitting on the tile floor.
sitting on the carpeted floor. sitting on the wood floor.
terminal velocity gravity will accelerate an object until air resistance (friction) does not allow it to go any faster.
In the absence of air resistance, which of these objects will fall at the fastest rate when dropped?
the ball with a mass of 75 kg
the ball with a mass of 25 kg
the ball with a mass of 10 kg
They all fall at the same rate.
Gravitational force
Gravitational force
Gravitational forceo INCREASES with Masso DECREASES with Distance
All objects in the universe are attracted to each other by the force of
effort.
friction.
gravity.
inertia.
THE END
• Do Q 1-7, P413
Four pairs of objects have the masses shown below. If the objects in each pair are the same distance apart, the gravitational force between the objects in which pair is greatest?
1 kilogram and 1 kilogram
1 kilogram and 2 kilograms
2 kilograms and 1 kilogram
2 kilograms and 2 kilograms
Four pairs of objects have the masses shown below. If the objects in each pair are the same distance apart, the gravitational force between the objects in which pair is greatest?
1 kilogram and 1 kilogram
1 kilogram and 2 kilograms
2 kilograms and 1 kilogram
2 kilograms and 2 kilograms
Simple Machines and work
Lever Inclined plane Pulley Wedge Screw Wheel and axle
Simple Machines and work
Lever Inclined plane Pulley Wedge Screw Wheel and axle
Simple Machines• Pulley• Wheel &
Axle• Lever• Inclined plane• Screw• Wedge• Gear
Simple MachinesSimple MachinesPulley
Wheel & Axle
Lever
Pulley
Wheel & Axle
Lever
Inclined plane
Screw
Wedge
Gear
Inclined plane
Screw
Wedge
Gear
Which activity involves the use of a simple machine?
riding on a seesaw
flying a kite
listening to a radio
skiing down a hill
Simple MachineSimple Machine
A mechanism that lowers the amount of force needed to do work, by increasing
the distance.
A mechanism that lowers the amount of force needed to do work, by increasing
the distance.
On which simple machine is a fulcrum found?
pulley
wheel
axle
lever
Which of the following is often used as a lever?
file
nail
saw
crowbar
The WedgeThe Wedge
The bottom of this light bulb is an example of what type of simple machine?
a lever
a pulley
a screw
a wedge
What type of simple machine is used to split things apart?
screw
wheel and axle
wedge
inclined plane
What type of simple machine is used to pull a flag up to the top of a flagpole?
screw
wheel and axle
inclined plane
pulley
Centripetal force The inward force on a spinning object,that stops it from going in a straight line.
Perpendicular
Centripetal force
Centripetal force The inward force on a Spinning object.
Centripetal force The inward force on a Spinning object.
Centripetal force The inward force on a Spinning object.
Centripetal force The inward force on a Spinning object.
Satellites stay in place as they orbit because of . . .
the repeated firing of rocket boosters.
the gravitational pull of Earth.
a narrow path through the vacuum of space.
solar panels generating energy to hold them in place
