Grade 10 Science Physics: Forces

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Grade 10 SciencePhysics Forces
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What is Force?
Force is a push or a pull on something.
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Which of the following objects feels a force?
A soccer ball being kicked
Foot pushes, Gravity pulls
A book sitting on a table
Gravity pulls, Table pushes up
An airplane flying
Gravity pulls, Air pushes back
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Which of the following objects feels a force?
A rock in deep space
No force, No gravity
The space shuttle orbiting Earth
Gravity pulls
The Earth
Suns and moons gravity pulls
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Which of the following objects feels a force?
A calculator sliding across a desk
Gravity pulls, desk pushes back
You, right now
Gravity pulls, chair pushes up
A fish in the ocean
Gravity pulls, air inside pushes up
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All things at all times on Earth feel one or more
forces.
__________ pulls things towards the centre of the
earth.
Gravity
__________ pushes against things that are moving.
For example, cars feel air resistance.
Friction
__________ forces push against other forces. For
example, a table pushes up on a book.
Normal
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All things at all times on Earth feel one or more
forces.
__________ forces push or pull things that have
an electric charge.
Electric
__________ forces push or pull things that are
magnetic.
Magnetic
The ________________ force keeps the nucleus
inside the atoms together.
nuclear strong
The ________________ force makes atoms change
into different atoms.
nuclear weak
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Try to list as many forces as you can that affect
the soccer ball
Sitting on the ground
Gravity, normal from the ground
On the ground getting kicked
Gravity, normal on the ground, push from foot
Flying through the air after being kicked
Gravity, air resistance
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Try to list as many forces as you can that affect
the soccer ball
Rolling on the ground
Gravity, normal from the ground, air resistance,
ground resistance
Rolling to a wall and bumping into it
Gravity, normal from ground, normal from wall
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What is Net Force?
Net force makes things change their motion.
Net force all forces added together
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1. A car driving on a straight road at a
constant speed of 50 km/hr.
Motion Changing
No
Net Force
No
2. A car driving on a straight road speeding up.
Motion Changing
Yes
Net Force
Yes
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3. A car driving on a straight road slowing down
to stop.
Motion Changing
Yes
Net Force
Yes
4. A car stopped at a red light.
Motion Changing
No
Net Force
No
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5. A car driving on a curved road at a constant
speed of 50 km/hr.
Motion Changing
Yes
Net Force
Yes
6. A car falling straight down towards the ground
faster and faster after going off a cliff.
Motion Changing
Yes
Net Force
Yes
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7. A car falling straight down towards the ground
at a constant speed of 250 km/hr.
Motion Changing
No
Net Force
No
8. The cars parachute starts to open and the car
falls straight towards the ground more and more
slowly.
Motion Changing
Yes
Net Force
Yes
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9. The parachute is fully opened and the car
falls straight towards the ground at a constant
speed of 30 km/hr.
Motion Changing
No
Net Force
No
10. Based on your answers to questions 1 to 9,
does a car need a net force to move?
NO!!!
11. Based on your answers to questions 1 to 9,
what does a net force do?
It causes the car to change its motion.