Transcript Newton*s Laws Review

 What
is motion?
 Motion
is when an object changes its
position.
 Motion can be represented
mathematically through calculations of
speed, velocity, and acceleration
 Motion is when an object changes its
position.
 Velocity
has speed and direction.
Velocity = distance + direction
time
 Displacement
is the distance and
direction between the starting and
ending position.
A car moved 60 km East and 90 km West.
What is the distance?
What is the total distance? __________ ___
What is the displacement? __________ ___
A
bike rider biked 50 km North and 30
km South. What is the displacement?
What is the total distance? __________ ___
What is the displacement? __________ ___
 Later
that day, they decided to work on
their fitness and go run the track. They
headed 60 meters southwest from their
rooms to the track which took them 20
seconds. What is their velocity?
v = d+direction
t
d
= 60 m SW
t = 20 sec
v=?
v = 60 m SW
20 sec
v = 3 m/sec/SW
 The
distance an object travels in a certain
amount of time.
Average speed – Total distance divided
by total time
Constant speed - Speed that does not
change
 Speed
equals distance divided by time.
 Speed = Distance ÷ Time
Create the triangle
A
football field is about 100 meters long.
If it takes a person 20 seconds to run its
length, how fast was the football player
running?
 Speed
= Distance ÷ Time
Speed = 100 m ÷ 20 s
Speed = 5m/s
A
change in the direction or speed
(velocity) of an object over time – which
may be:
-A change in speed
–Starting
–Stopping
–Speeding up (positive acceleration)
–Slowing down (negative acceleration)
-A change in direction
Acceleration is caused by unbalanced
forces
 m/s
s
Unit for Acceleration
km/hr
s
 If
a car is moving on a road at 70 km/hr
going due north, and then changes
direction and starts traveling northeast
staying at 70 km/hr, what happens to its
speed and velocity?
A
The speed of the car changes, but the
velocity stays the same.
B The velocity of the car changes, but
the speed stays the same.
C Both the speed and velocity of the car
change.
D Neither the speed nor the velocity of
the car changes.
A
2000 kg truck and a 500 kg car are
racing. The same amount of force is
applied to each of them. What will
happen?
A
The truck will accelerate twice as
fast.
B The car will accelerate twice as fast.
C The truck will accelerate four times as
fast.
D The car will accelerate four times as
fast.
 Martin
gathered a toy car, a ramp, a
stopwatch, a meter stick, and a variety of
weights. What is he likely testing?
A
how the angle of a ramp affects the
speed of the car
B how friction affects the speed of the
car
C how equal forces work on the
placement of the car and the ramp
D how mass affects the speed of the car
 What
is the speed of a train that runs
4200 km in 21 hours?
s=d/t
 s=
4200/21
s= 200 km/hr
 Two
people head 60 meters southwest
and it took them 20 seconds. What is their
velocity
v= distance+ directions
-----------------------------------time
*remember velocity is speed and
direction
 d=
60 m sw
t= 20 sec
s=?
v= 60/ 20
v= 30 m/s sw
 The
cause of motion (what causes objects
to move)
 Force
has four components: push, pull,
size, and direction
 Force
always come in pairs. It’s
impossible to have only one force
 Symbol: N
•Measured by using a spring scale
•What is a newton? A newton is a force
required to accelerate a one kg mass at
a rate of one m/s2.
 Net
Force: Net force is the sum of all
the forces acting on an object
•If the forces are in the SAME
direction, then you add them together.
5 N --------> 5 N----------->
•If the forces are in opposite directions
then you subtract the smaller force
from the larger force.
10 N ------>
<---------5N
 Balanced
forces – all forces acting on an
object are equal
–There is NO MOTION
•Unbalanced forces – one or more
forces acting on an object are stronger
than others
–There is MOTION
•A NET FORCE
 Balance
force describes forces that are
equal but opposite in direction; when
they act on an object, they cancel each
other out and no change occurs in the
object’s motion.
 •Unbalanced
forces describe unequal
forces acting on an object. This results in
a change in the object’s motion in the
direction of the larger force.
CBA
What
is the formal name for
Newton’s 1st Law?
A. The Law of Action/Reaction
B. The Law of Inertia
C. The Law of Force and Acceleration
Which
law states that “for every
action, there is an equal and
opposite reaction”?
A. Newton’s 1st Law
B. Newton’s 2nd Law
C. Newton’s 3rd Law
What
is the formal name for
Newton’s 2nd Law?
A. The Law of Action/Reaction
B. The Law of Inertia
C. The Law of Force and Acceleration
Which
law states, “an object acted
on by an unbalanced force will
accelerate in the direction of the
force”?
A. Newton’s 1st Law
B. Newton’s 2nd Law
C. Newton’s 3rd Law
What
is the formal name for
Newton’s 3rd Law?
A. The Law of Action/Reaction
B. The Law of Inertia
C. The Law of Force and Acceleration
Which
law states, “an object in
motion tends to stay in motion and
an object at rest tends to stay at rest
until acted upon by an unbalanced
force”?
A. Newton’s 1st Law
B. Newton’s 2nd Law
C. Newton’s 3rd Law
A
book is sitting on the table at
rest. The forces acting on the book
include _______, and these forces
are _______.
A. Gravity pushing down and the table
pushing up; balanced
B. Gravity pushing down and the table
pushing up; unbalanced
C. Gravity pushing up and friction
pushing to the right; balanced
 Tom
is teaching Jenny how to ice
skate. Both skaters, who are about the
same size, are on the ice and wearing
their skates. To help Jenny get started,
Tom gives her a gentle push from behind.
Which of the following best describes
what will happen next?
A. Jenny will move backward; Tom will
move forward
B. Jenny will move forward
C. Jenny will move forward; Tom will move
backward
What
are the four components of
force?
A. Push, Pull, Speed, Direction
B. Push, Size, Speed, Direction
C. Push, Pull, Size, Direction
Which of the following best describes the
difference between speed and acceleration?
A. Acceleration is the distance an object travels
within a specific unit of time; speed is the
measure of the force necessary to change the
acceleration of an object
B. Speed is the distance an object travels within a
specific unit of time; acceleration is a measure
of the force necessary to change the speed of
an object
C. Speed is the distance an object travels within a
specific unit of time; acceleration is the rate at
which the speed or direction of an object is
changing

How
much force is needed to
accelerate a 2,000 kg car at a rate of
8 m/s2?
A. 24,000 N
B. 4,000 N
C. 16,000 N
Which of the following best explains why Reggie's
books fell?
A. When Reggie's car turned eastward, his books
continued heading northward, causing them to slide
off the top of his car and fall.
B.
The Earth's magnetic field held the books on Reggie's
car while he headed north.When he turned east, the
magnetic pull faded, causing the books to fall.
C. Heat energy from the Sun caused Reggie's books to
slide off the top of his car and fall.

If
Sara's father presses on the brakes
quickly slowing the car down, what
slows Sara down?
A. the seat pushing forward on her
B. her seat belt pulling back on her
C. air resistance on the outside of the
car
Jodie
sets two objects on a flat
surface. Object A has a mass of 50g,
while object B has a mass of
250g. Jodie pushes both objects with
the same force and watches them
accelerate.Which object will
accelerate more?
A. Object B accelerates more.
B. Object A accelerates more.
C. They accelerate the same amount.
A
car is traveling south at a speed of
65 miles per hour and then begins
traveling west but continues
traveling at the same speed. Which
of the following has changed?
A. Speed
B. Mass
C. Velocity
A.
B.
C.
A player added to Team B pulls on the rope
with a force of 120 newtons.
A player added to Team A pulls on the rope
with a force of 130 newtons.
A player on Team B who was pulling with a
force of 150 newtons leaves the game.
 To
test this statement, Martin rolled a ball on a
long, level street. The ball did not bump into
any object, but it eventually came to a
stop. How is this possible?
A. Every moving object must come to a stop
because energy cannot be destroyed.
B. Martin did not roll the ball hard enough,
which caused the ball to eventually stop
rolling.
C. The unbalanced force that caused the ball to
stop was friction.
What
A.
B.
C.
is the definition of inertia?
The tendency of a body at rest to
stay at rest or of a body in motion to
remain in motion.
The tendency of an object in motion
to decelerate.
The rate at which an object
accelerates.
The
theories of continental drift and
sea-floor spreading combined to
make the theory of _______.
A. plate tectonics
B. rejoined continents
C. Pangaea
 The
Atlantic Ocean is currently
growing wider as its floor enlarges due
to the process of sea-floor
spreading. In sea-floor spreading,
pieces of oceanic crust
A. move sideways against each other
along a transform plate boundary.
B. move together along a convergent
plate boundary.
C. move apart along a divergent plate
boundary.
A
tectonic plate applies a downward force
onto the asthenosphere, which lies beneath
the plate. According to Newton's 3rd Law,
which can be described as the law of actionreaction,
A. the asthenosphere applies a force of
double magnitude upward onto the
tectonic plate.
B. the asthenosphere applies a force of equal
magnitude upward onto the tectonic plate.
C. the asthenosphere applies a force of equal
magnitude downward as well.
A.
B.
C.
a sand dune
a delta
a barrier island
A
subduction zone is an area where one
tectonic plate sinks underneath another
one.Volcanoes often form as a result.Which
of the following plate collisions would most
likely result in a subduction zone?
A. a piece of continental crust and a piece of
oceanic crust meeting at a convergent
boundary
B. two pieces of oceanic crust meeting at a
divergent boundary
C. a piece of continental crust and a piece of
oceanic crust meeting at a divergent
boundary
Which
of the following provides the
most evidence for the theory of plate
tectonics?
A. the spreading of the sea floor
B. the locations of the glaciers
C. the changing of the seasons