S8P3
Students will investigate relationship
between
force, mass, and the motion of objects.
Determine the relationship between
velocity and acceleration
Velocity is a speed in a specific
direction.
Example: Sam is walking east at a
speed of 3 m/s. Joe walking
north at a speed of 3 m/s would
have the same speed but not the
same velocity.
Acceleration is a measure of how
quickly the velocity is changing.
If the velocity does not change,
there is no acceleration.
The word acceleration is
commonly used to mean
“speeding up”, however,
acceleration refers to any change
in velocity (speed or direction).
Acceleration
1. Acceleration in the same direction- the speed
of the object increases. The car speeds up.
2. Acceleration in the opposite direction- The
car slows down. Slowing down is a negative
acceleration.
3. Acceleration at a right angle- The direction of
the car changes, but its speed does not
change.
Demonstrate the effect of balanced and
unbalanced forces on an object in terms of
gravity, inertia, and friction.
Net force is the overall force acting on an object
when all the forces are combined.
Balanced forces have the same effect as no force at
all.
An unbalanced force can change the motion of an
object.
Inertia is the resistance of an object to a change in
the speed or the direction of its motion
“Newton’s first law”.
Newton’s first law- States that objects at rest
tend to stay at rest, and objects in motion will
continue in motion unless acted on by an
outside force.
Newton’s second law- Force equals mass times
acceleration. F=ma
Newton’s third law- States that every time one
object exerts a force on another, the second
object exerts an equal and opposite force on
the first object.
Demonstrate the effect of simple
machines (lever, inclined plane, pulley,
wedge, screw, and wheel and axle)
on work.
• Work occurs when a force causes an object to
move in the direction of the force.
• Simple machines change the size or direction
(or both) of the input force and make work
easier. Using a simple machine does NOT
mean you do less work.
Simple machines are six machines on which all
other mechanical machines are based.
A lever is a solid bar that rotates, turns, around
a fixed point.
First Class
Second Class
Third Class
Wheel and axle
A wheel and axle is a simple machine made up
of a wheel attached to a shaft, or axle.
Pulley
A pulley is a wheel with a grooved rim and a
rope or a cable that rides in a groove.
Inclined Plane
An inclined plane is a simple machine that is a
sloping surface.
Wedge
A wedge is a simple machine that has a thick
and a thin end.
Screw
A screw is an inclined plane wrapped around a
cylinder or cone to form a spiral.