Untitled Flashcards Set

Motion - a change of location, always relative to something else

Reference Frame - perspective from which the motion of something is measured

Speed - How fast an object moves

Velocity - Provides both speed of an object and the direct of its motion

Momentum - mass in motion, depends on the object's mass and velocity

Conservation of Momentum -  If outside force are not act on a system of objects, their total momentum never changes

Elastic Collisions - All the momentum entering the collision is present as momentum leaving the collision

Inelastic Collisions - Some kinetic energy is transferred into other forms of energy

Acceleration - A change in speed or direction

Deceleration - negative acceleration 

Inertia - the reluctance of an object to change it state of motion

Force - A net "push" or "pull" that changes the velocity of an object

Net Force - the sum of all the forces acting on the object

Balanced Force - occurs when the net force is zero

Unbalanced Force - occurs when the net force is nonzero, meaning acceleration

Friction - the resistance that one surface or object encounters when moving over another

Gravity - a force that pulls objects with mass towards each other

Weight - the force acting on an object due to gravity

Free Fall - falling toward the earth only under earth’s gravity 

Air Resistance - the force that slows down an object moving through air

Terminal Velocity - the constant speed that a falling object reaches when the force of air resistance (drag) acting on it equals the force of gravity pulling it down, resulting in no further acceleration and a steady rate of descent

Projectile Motion - the motion of an object (called a projectile) that is thrown or projected into the air, where the only force acting on it after the initial launch is gravity, causing it to follow a curved path (trajectory)

Circular Motion - the movement of an object along a circular path, where the object constantly changes its direction while maintaining a fixed distance from a central point

Centripetal Force - inward force on an object moving along a curved path

Hooke’s Law - F = k x change in L

Stress - the force acting on a unit area of a material, essentially measuring the intensity of force distributed across a surface

Strain -the measure of deformation a material experiences when subjected to an external force

Tension - the pulling force transmitted along the length of a flexible object like a rope, string, or cable, when it is stretched by forces acting from opposite end

Work - Applying force that moves an object through some distance

Simple Machine - a mechanical device with few or no moving parts that can change the direction or magnitude of a force applied to an object

Mechanical Advantage - the ratio of the output force produced by a machine to the input force applied to it

Newton’s First Law - Inertia - an object at rest or at constant velocity unless its acted on by an unbalanced force

Newton’s Second Law - the acceleration of an object is equal to the net force acting on it divided by its mass. F = MA

Newton’s Third Law - for every action there is an equal and opposite reaction

What is the value for the acceleration due to gravity on earth?

 9.8 m/s

What is the difference between speed and velocity? -  Velocity is associated with a direction

What is the difference between mass and weight? 

Mass is the amount of matter present.  Weight is the amount of force gravity pulls on that matter with.  Weight depends on gravity, but mass does not.

If you were given that the acceleration of a car had a negative value, what would this mean?

The velocity is being decreased, or increasing in a negative direction.

If we were to look at your mass on different planets what would we find? 

 Mass is the same

If we were to look at your weight on different planets what would we find?

 Weight changes as gravity changes

What happens to the gravitational attraction between objects as the distance between the objects increases? 

 The attraction decreases with increased distance. Doubling distance reduced gravitational attraction by ¼.  That is what r² in the denominator of the equation indicates.

As the mass of an object increases what happens to the gravitational attraction on the object?

 The gravitational attraction increases proportionally with the increased mass:  double mass, double gravity

Give an example of a situation in which the net force is an unbalanced force.

 If any acceleration takes place, it means there is an unbalanced force at work. Turning a car is an example.  (If forces are balanced, the car’s motion will not change.)

Give an example of a situation in which the net force is a balanced force. 

 When a cup sits on a table, the pull of gravity is matching by the reaction force

Why does a football at rest tend to remain at rest?

 Because of its inertial mass

In a vacuum, which will fall faster:  A bowling ball or a marble?

 They will fall the same speed without drag

What does it mean if the line on a graph of distance traveled over time becomes steeper?

 Mor distance is covered over time: the speed is increasing 

If a father is skating across a pond at a steady speed, and scoops up his daughter as he goes by, what happens to his speed?  Why?

Since he adds his daughters mass, the momentum is conserved. Since the mass went up the velocity decreased