Term
Which component, horizontal or vertical, of an object's velocity remains constant as a projectile travels? 

Definition


Term
If the action force is the earth pulling on a feather, what is the reaction force? 

Definition
the feather pulling on the earth 


Term
If a cliff diver carried a speedometer on his dive, by how much would the reading increase each second? 

Definition


Term
If a car moves 29 meters in one second, 29 meters in the second second, and 29 meters in the third second of travel, what is its acceleration? 

Definition


Term
When you look at the speedometer in a car the number reflects the ______________ velocity of the car. (instantaneous or average) 

Definition


Term
Why doesn't the horizontal component of velocity change during the flight of a projectile? 

Definition
because there are no forces acting in the horizontal direction 


Term
If a crumpled piece of paper and a flat sheet of paper fall which will hit the ground first? 

Definition
the crumpled piece because it is affected less by air resistance 


Term
If the upward direction is positive, during the flight of a projectile, the acceleration on the object is: positive negative positive then negative negative then positive 

Definition


Term
If you increase the velocity of an object, which of the following quantities increases: momentum, kinetic energy, force 

Definition
momentum and kinetic energy 


Term
A ball hits a bat. Compared to the force of the bat on the ball, the force of the ball on the bat is ____________. 

Definition


Term
Gravitational potential energy depends on what three things? 

Definition
mass of the object, the acceleration due to gravity and the object's height above the ground 


Term
Elastic potential energy depends on the spring constant (stiffness of the spring) and ______________. 

Definition


Term
In the absence of air resistance, which will hit the ground first: an egg or feather? 

Definition
they will hit at the same time 


Term
The rate at which work is done 

Definition


Term
The quantity of work done divided by the time it takes to do the work 

Definition


Term
If at the same instant a bullet is dropped and another is shot perfectly straight forward at the same height, which will hit the ground first? 

Definition
they will hit at the same time 


Term
________ causes acceleration. 

Definition


Term
If an object is moving in a circle is it accelerating? 

Definition


Term
Can an object accelerate without changing speed? 

Definition
yes, by changing direction 


Term

Definition
For every action force, there is an equal and opposite reaction force 


Term
Which of Newton's Laws is behind the trick of pulling the table cloth out from under a place setting and having the place setting remain in the same position? 

Definition
Newton's First Law (objects at rest remain at rest unless acted on by a force) 


Term
A ball is falling, each second it falls it covers ____________ distance. more the same less 

Definition


Term
If you double the distance you push an object but apply the same amount of force, how does the work change? 

Definition


Term
Newton's first law can be stated in one word: ___________. 

Definition


Term
At the top of a projectile's path, its acceleration is ____________. 

Definition


Term
If the acceleration of an object with constant mass doubles, what else has doubled? 

Definition
the force acting on the mass 


Term
Gravity acts in which direction? 

Definition


Term
What type of friction could be referred to as moving friction? 

Definition


Term
Inertia is directly related to what property of an object? 

Definition


Term
What type of friction is nonmoving friction? 

Definition


Term
Traveling to another planet, which measurement changes mass or weight? 

Definition


Term
What unit is used to measure mass? 

Definition


Term
The product of force and distance 

Definition


Term
State the law of conservation of energy 

Definition
Energy cannot be created or destroyed 


Term
What really happens when energy is "lost"? 

Definition
It is transformed into another kind or transferred to another object 


Term
If a runner increases his speed from 0 m/s to 3 m/s in the first second and 3 m/s to 6 m/s in the second second, what is his acceleration? 

Definition


Term
What quantities use joule as the unit? 

Definition
kinetic energy, potential energy, work 


Term
If you are on rollerskates moving in a positive direction and begin to slow down, your acceleration is in which direction? 

Definition


Term
A quantity with magnitude and direction 

Definition


Term
What direction does friction act in? 

Definition
the direction opposite motion 


Term
How is the force of friction oriented relative to the surface of contact? 

Definition


Term
The normal force is ____________ to the surface of contact 

Definition


Term

Definition
bumps on the two surfaces in contact 


Term
Describe the energy change in a roller coaster as it moves up a hill. 

Definition
the energy changes from kinetic to potential 


Term
Where does a projectile have minimum speed? 

Definition
at the top of its path (vertical velocity is zero) 


Term
In the absence of friction, if a roller coaster is going 30 m/s before it crests a hill, how fast should it be going when it reaches the same position (height) on the way down the hill? 

Definition


Term
A book is on a table, the force pushing back on the book is the _____________ force. 

Definition


Term
The product of 1/2 the mass of an object times the velocity squared 

Definition


Term
Force and acceleration are _______________ related. (directly, inversely) 

Definition


Term
Watts are the unit for _________. 

Definition


Term
Mass and acceleration are ___________ related. (directly, inversely) 

Definition


Term
If you do 10 J of work to lift an object, how much potential energy does it have? 

Definition


Term

Definition


Term
If you are walking forward and toss a ball in the air, where will it land? behind you in front of you in your hand 

Definition

