Motion and Force
What is acceleration of a 500 Newton person going from 0 to 10 m/s in five seconds?
10-0/5= 2 m/s/s forward
A motorcyclist travels 500 km in 5 hours. What is his average speed?
100 km/hr
What is the action force?
Bird's wings pushing down on the air
The more mass an object has the more __________ it will take to move the object from rest or stop the object once it is in motion.
force
Type of force that is equal and opposite to the weight (or gravity) force.
normal force
Define Force
A push or pull exerted on an object
What is the action force?
Man pushing down on the diving board
A driver is traveling east on a dirt road when she spots a pothole ahead. She slows her car from 14.0 m/s to 5.5 m/s in 6.0 s. What is the car's acceleration?
-1.4 m/s/s east
Which of the following force diagrams shows a box that could be moving at a constant speed?
D, it shows balanced forces or a net force of zero.
What is the reaction force?
Diving board pushing up on the man
A magician pulls out the tablecloth from under the dishes and they do not move.
Newton's First Law of Motion
A person's body is thrown outward around a curve.
Newton's First Law of Motion
A picture hanging on the wall does not move.
Newton's First Law of Motion
An object at rest will remain at rest and an object in motion will remain in motion until acted upon by an unbalanced force.
Newton's First Law of Motion
An object in motion will remain in motion unless acted upon by another force
Newton's First Law of Motion
The Law of Inertia.
Newton's First Law of Motion
You are pushed back into your seat when an airplane takes off.
Newton's First Law of Motion
A pitched baseball goes faster than one that is gently thrown.
Newton's Second Law of Motion
An ice skater pushes with more force and begins to move faster.
Newton's Second Law of Motion
Force = mass x acceleration
Newton's Second Law of Motion
It takes less force to move a bicycle than a motorcycle.
Newton's Second Law of Motion
It takes more force to move a bowling ball than a baseball.
Newton's Second Law of Motion
The FORCE of an object is equal to its MASS multiplied by its ACCELERATION.
Newton's Second Law of Motion
I am one of Newton's Laws that always involves two objects and two forces. Which Law am I? - Newton's First Law - Newton's Second Law - Newton's Third Law
Newton's Third Law
A cannonball shot forward and the cannon moves back.
Newton's Third Law of Motion
A fireman turns on his hose and is knocked backwards.
Newton's Third Law of Motion
A swimmer pushes back on the water and moves forward.
Newton's Third Law of Motion
For every action there is an equal and opposite reaction
Newton's Third Law of Motion
the total displacement / the total time
average velocity
speed that stays the same over time
constant speed
What is this graph showing?
constant speed - Speed/Time Graph
What is this graph showing?
constant speed - getting farther away - Graph Distance/Time
An example involving action-reaction forces is____. a. air escaping from a toy balloon b. a rocket traveling through the air c. a ball bouncing off a wall d. all of the above
d. all of the above
What is the average speed between 2 and 4 seconds?
distance is 40-20=20 time is 4-2=2 therefore, 20/2=10 m/s
An object with more mass has more __________.
inertia
The less mass an object has the less force it will take to move the object from rest or __________ the object once it is in motion.
stop
The more mass an object has the more force it will take to move the object from rest or __________ the object once it is in motion.
stop
change in velocity over time
acceleration
Inertia
A measure of an object's resistance to change in motion.
This is the term for the force with which gravity pulls on a quantity of matter
weight
net force
The sum of all the forces acting on an object.
A car moving at 2 m/s maintains its speed of 2 m/s for 2 seconds. What is the acceleration?
0 m/s/s
A snail travels the distance of 25 meters in two days. What is its speed in meters per hour?
0.52 m/hr
How much time will it take a cheetah to run 200 m at a speed of 20 m/s?
10 s
What is the acceleration of a car that goes from 4 m/s to 10 m/s in 3 seconds?
2 m/s/s
What is the net force acting on this block?
11 N to the right (box will accelerate to the right)
A car moving at 5 m/s accelerates at 2 m/s/s for 3 seconds. What is its final speed?
11 m/s
A trip to Atlanta Georgia took 10 hours in a car. The distance was 1,100 km. Calculate the average speed traveled throughout the trip.
110 km/hr
Mary can travel at 20 mi/hr on her bike. How far will she go if she rides for 0.75 hr?
15 miles
An average bullet travels approximately 90m in 0.5 seconds. What is it's speed?
180 m/s
A car starting from rest accelerates at 3 m/s/s for 8 seconds. What is its final speed?
24 m/s
Which of Newton's Laws describes the relationship between the mass and force? - 1st Law of Motion - 2nd Law of Motion - 3rd Law of Motion
2nd Law of Motion
A car starts from rest and attains a speed of 12 m/s is 4 seconds. What is the acceleration?
3 m/s/s
speed up, slow down, change direction
3 ways to accelerate
Orville Wright's first powered airplane flight lasted only 12 seconds. He was in the air for a distance of 37 meters. What was his whopping speed??
3.08 m/s
A woman can walk in high heels for a distance of 1 kilometer in 15 minutes. What is her speed in km/hr?
4 km/hr
A car starting from rest accelerates at a rate of 5 m/s/s to a final speed of 20 m/s. How much time does this take?
4 s.
A snail can crawl at a speed of 0.75 cm/s. How long will it take the snail to crawl 3 cm?
4 seconds
What is the acceleration of a car going 55 m/s and then slows to 40 m/s in 5 sec?
40-55/5=-3 m/s/s forward
How far does a bowling ball travel at a speed of 9.8 m/s if it rolls for 5 s?
49 m
How long will a trip take (in hours) if you travel 350 km at an average speed of 70 km/hr?
5 hours
Tina's calculations of a tarantula found that the spider was able to cover 20 cm at a speed of 4 cm/s. How long did it take the spider to travel this distance?
5 s
A girl takes 30 mins to travel around a cross- country ski course: a distance of 10 km. Calculate her average speed in m/s
5.56 m/s
Traveling at a speed of 100 km/hr, how far will a bus travel in half an hour?
50 km
What does this graph show?
acceleration on a speed vs. time graph
A car starting from rest accelerates at a rate of 8 m/s/s to a final speed of 64 m/s. How much time does this take?
8 s.
What is the average velocity of a commercial jet that travels from New York to Los Angeles (a distance of 4,800 km) in 6 hours?
8oo km/hr west
What is the reaction force?
Air pushing up on the bird's wings
Forces that result in no change in an object's motion.
Balanced Forces
What does this graph show?
Constant speed on a distance vs. time graph
What does this graph show?
Constant speed on a speed vs. time graph
What is the action force?
Foot pushing down on the ground
__________ = mass x acceleration
Force
At-a-distance forces
Force field forces like electricity, magnetism, and gravity.
Contact forces
Forces that must be in contact with the object and include friction and applied force and air resistance.
What opposes motion between surfaces touching?
Friction
What is the action force?
Gravity pulling down on the book
What is the reaction force?
Ground pushing up on the foot
Newton's First Law is also called the __________ of __________.
Law of Inertia
A vector is a quantity represented by an arrow showing both __________ and _____________
Magnitude and Direction
You are on vacation on a beautiful beach. Everyday when you walk on the beach your foot presses into the sand and leaves a footprint, but you don't sink into the sand. Why does your whole body not sink into the sand and which of Newton's Laws explains this situation?
My whole body doesn't sink into the sand because the sand is pushing back up against my foot. Newton's Third Law explains this situation.
What number shows constant speed, away from the original starting place?
Number #1
What number shows an object at rest?
Number #2 and #5
What number shows an object moving at a slower speed, traveling back in the direction came from
Number #3
Which number shows an object moving at a faster speed? (look at slope of the line)
Number #4
Which number shows the fastest speed shown on this graph, back to the starting place?
Number #6
What does this graph show?
Object at rest (0 m/s) on a distance vs. time graph
What does this graph show?
Object at rest (0 m/s) on a speed vs time graph
Choose the line on the distance vs. time graph for a person who jogged away from his house at a constant rate, rested for a longer time than he jogged, then turned around and returned home jogging at a constant rate.
Red line
According to Newton's Second law of motion; if the same force is applied to a small mass and a large mass and all other conditions are the same, the large mass will have a ______________ _________
Smaller Acceleration
What does the slope on a distance vs. time graph represent?
Speed
Friction
The force that resists motion
What is the reaction force?
Table pushing up on the book
What would the line on a distance time graph look like if an object was increasing in speed?
The blue line
According to Newton's First Law of motion... If a girl were riding a sled down hill moving at 15 mph and the sled suddenly stopped, what would happen to the girl?
The girl would continue to move in the direction the sled was moving at 15 mph until an outside force acts upon her.
For every action force there is an equal and opposite reaction force.
What is Newton's Third Law of Motion?
The rate of change of speed over time.
What is acceleration?
the total distance traveled divided by the total time
What is average speed?
Speed in a given direction.
What is velocity?
Force = mass x __________.
acceleration
For every action force there is an __________ and opposite reaction force.
equal
On a distance vs. time graph, the steeper the slope the ______________ the speed.
faster
Type of friction that occurs when an object moves through a fluid (gas or liquid).
fluid friction
The less mass an object has the less __________ it will take to move the object from rest or stop the object once it is in motion.
force
A force that will work against motion in every situation is...
friction
What is this graph showing?
graph showing constant acceleration
What is this graph showing?
graph showing object is stopped
If the object is NOT moving, where is the acceleration coming from to cause the force to increase as the mass increases? - friction - spin of Earth - gravity - movement around the Sun
gravity
You are riding in a vehicle with a coffee cup on the dashboard while traveling 30 km/h. The vehicle makes a sudden stop to avoid hitting the car that has stopped in front of it. What would happen to the coffee cup? - it would move forward - it would move backward - it would stay stationary - it would move straight up
it would move forward
When a car suddenly stops, the objects in the back seat are thrown forward. This is due to __________. - law of gravitation - law of force and acceleration - law of inertia - law of action / reaction
law of inertia
The less __________ an object has the less force it will take to move the object from rest or stop the object once it is in motion.
mass
The more __________ an object has the more force it will take to move the object from rest or stop the object once it is in motion.
mass
What 2 factors affect gravity?
mass and distance
What happens to mass and weight if an astronaut goes into space?
mass stays the same and weight changes
When you push a crate up a ramp the crate is __________ back on you.
pushing
For every action force there is an equal and opposite __________ force.
reaction
used to determine if an object is moving
reference point
The less mass an object has the less force it will take to move the object from __________ or stop the object once it is in motion.
rest
The more mass an object has the more force it will take to move the object from __________ or stop the object once it is in motion.
rest
Type of friction that occurs when one surface rolls along another surface.
rolling friction
The type of friction that occurs between two surfaces that are in contact and are sliding against each other.
sliding friction
What does this graph show?
slowing down on a speed vs. time graph
Velocity is defined with both _________ and _________
speed and direction
What is the strongest type of friction?
static
The type of friction that exists between two surfaces that are in contact, but are NOT moving.
static friction
A rocket is traveling from Earth to Mars at 10,000 m/sec. If no outside force is applied to it, what will happen to its speed over the course of the trip? - speed up - slow down - stay constant - changes depending on mass
stay constant
What unit do scientists use when measuring force?
the Newton (N)
During a tug-of-war competition, neither team is able to gain an advantage. Which of the following explains the forces in this situation? - the forces are balanced - the mass of the rope cancels the forces being exerted on it - the forces are unbalanced
the forces are balanced