Newton's Law 1
What causes a moving object to continue moving at the same velocity unless an unbalanced force acts on it?
Inertia
What is Gravitational Potential Energy
The amount of potential energy is determined by its height and mass.
The higher an object, the greater its potential energy
Ex) a ball before its bounced, a car parked on top of a hill, a yo-yo before its released
The following picture shows the forces acting on a sneaker. Suppose that the sneaker is moving toward the spring scale. In this situation, which pair of forces is balanced
A. The applied force and friction
B. The applied force and the normal force
C. The gravitational force and the applied force
D. The gravitational force and the normal force
Define Energy
The ability to do work and move or cause change in matter
What is Newton's 1st Law & What is is also called?
Double Points
An object in motion tends to stay in motion and an object at rest tends to stay at rest unless acted upon by an unbalanced force.
Law of Inertia
A moving object collides with a stationary object. Which of the following statements is true according to Newton’s third law of motion?
A. Each object exerts a force on the other, and the two forces are proportional to the masses of the objects
B. Each object exerts a force on the other, and the two forces are the same in magnitude and direction
C. Each object exerts a force on the other, and the two forces are equal and in opposite directions
D. The moving object exerts a force on the stationary object, but the stationary object does not exert a force on the moving object
What is Elastic Potential Energy
The energy stored in elastic materials as the result of their stretching or compressing.
The amount of energy stored is related to the amount of stretch applied.
The more stretch, the more stored energy
Ex) rubber bands, bungee chords, trampolines, springs, an arrow drawn
Blair and Aaron competed in a 400m running race. Blair finished the race in 55s and came in first. Aaron finished the race in 58s and came in second. Which of the following must have been greater for Blair than for Aaron?
A. His maximum speed during the race
B. His average speed for the entire race
C. His speed for the last 100m of the race
D. His initial speed for the first 100m of the race
What are the 2 types of Mechanical Energy
Potential & Kinetic Energy
What is Newton's 2nd Law & What is it also Called?
Force equals mass times acceleration
(F = ma).
Law of Force & Acceleration
A rock is sitting on top of a hill. The rock suddenly begins moving down the side of the hill. Why did the rock begin to move?
An unbalanced force acted on the rock and caused it to move
At a hydroelectric power plant, potential energy is changed into kinetic energy. The kinetic energy is then transformed into electrical energy. What is the source of the energy that turns the turbine in the power plant?
A. Chemical energy of water molecules as they fall
B. Gravitational potential energy of water behind the dam
C. Elastic potential energy of the water molecules as they bounce over the dam
D. Electrical energy from power lines that connect the hydroelectric plant to a grid
Montez read that bobcats can reach speeds of up to 30 mi/h. What does the speed of a bobcat indicate?
The distance it can travel in a certain amount of time
Every moving object has kinetic energy. This illustration shows four vehicles. Assume that they are all traveling at the same speed on a highway. What do you know about the kinetic energy of the vehicles?
A. The motorcycle has the most kinetic energy because it is the vehicle with the least mass
B. All of the vehicles have the same kinetic energy because they are moving at the same speed
C. The delivery van has the greatest kinetic energy because its mass is greater than that of the other vehicles
D. The delivery van has the greatest kinetic energy because it has the most tires in contact with the pavement
What is Newton's 3rd Law & What is it also called?
For every action there is an equal and opposite reaction.
Law of Action-Reaction
Luis is pushing a box of new soccer balls across the floor. In the picture below, the arrow on the box is a vector representing the force Luis exerted. What keeps the box from moving even though Luis is pushing on it?
A. The normal force is pushing against Luis’s force
B. The force of gravity is opposed to the force exerted by Lui
C. The equal and opposite force of friction prevents the box from moving
D. The force exerted by Luis on the box is not in the right direction to move the box
The Law of Conservation of Energy describes how the amount of energy can change in a closed system. Which of these statements correctly describes this law
A. The amount of kinetic energy in a system is a constant value
B. Energy can be converted from one form into another, but it cannot be destroyed
C. An object can have potential energy or kinetic energy, but not both at the same time
D. The amount of energy created when an objects moves is equal to the energy destroyed when it stops moving
The following graph shows the results of an experiment done by four different groups. Each group took a different rubber band and recorded how far it stretched as the added weights to it.
Which group’s rubber band stretched the least as more weight was added?
A. Group 1
B. Group 2
C. Group 3
D. Group 4
A rock on top of a hill has energy due to its position. What is this energy called?
Gravitational Potential Energy
What is Potential Energy
Potential EnergyStored energy in an object due to position
Ready to be used, but not being used
Can be transformed into other types of energy
SI unit Joule (J)Distance (height) and mass determine its measure
Found in all objects
Same Pic: What do the length and direction of the arrow represent in the picture?
A. The distance and direction of the motion of the box
B. The strength and direction of the force applied to the box
C. The motion of the box and the direction of the force applied to it
D. The strength and direction of the unbalanced force applied to the box
DAILY DOUBLE: 1000
The illustration below shows the path of a ball when thrown into the air.
At which point does the ball have the greatest amount of gravitational potential energy?
What energy does the ball have a point Y?
A. Point W
B. Point X
C. Point Y
D. Point Z
Kinetic energy and gravitational potential energy
Bo learns about the Law of Inertia. It states that objects at rest tend to stay at rest, and objects in motion tend to stay in motion. The state of motion changes only when another force acts on an object. Bo wants to use this law to predict how a soccer ball will roll on the grass after he kicks it.
Which statement best describes the motion of the ball?
A. The ball will keep rolling forever after he kicks it
B. The ball will not move because it is at rest when he kicks it
C. The ball will not move much after he kicks it because it wants to stay at rest
D. The ball will keep rolling until the force between the ball and the grass makes it stop
DAILY DOUBLE
Kylie drew this illustration to show what happens when a weight on a spring is pulled down and then released. Position 1 shows the spring at the start of the experiment. Position 2 shows how it looked when the weight was pulled downward. Position 3 shows what happened when she released the spring. Position 4 shows the spring just before the weight started to fall back down.
At which point does the spring have the greatest amount of gravitational potential energy
At which point does the spring have the greatest amount of mechanical energy?
Position 4
The mechanical energy is the same in all positions
The energy of motion
Formed or caused by motion
Can be transformed into other types of energy
SI unit Joule (J)Speed/velocity and mass determine its measure.
Found in all objects