physics 1 early flash cards

How do you determine location on a position-time graph?

Look at the vertical axis.

How do you determine speed on a position-time graph?

Look at the steepness (slope).

How do you determine direction on a position-time graph?

Look at which way the graph is sloped.

What does a front slash (/) slope mean on a position-time graph?

The object is moving away from the detector.

What does a back slash () slope mean on a position-time graph?

The object is moving toward the detector.

How is instantaneous velocity found on a position-time graph?

Take the slope of the tangent line.

What is Displacement?

How far an object ends up from its initial position, regardless of path.

What is Average Velocity?

Displacement divided by the time interval.

What is Instantaneous Velocity?

How fast an object is moving at a specific moment in time.

How do you determine speed on a velocity-time graph?

Look at the vertical axis.

How do you determine direction on a velocity-time graph?

Look at if the graph is above or below the horizontal axis.

On a VT graph, what does it mean if the line is above the axis?

The object is moving away from the detector.

On a VT graph, what does it mean if the line is below the axis?

The object is moving toward the detector.

How do you find distance traveled on a velocity-time graph?

Determine the area between the graph and the horizontal axis.

What can you NOT determine on a velocity-time graph?

How far the object is located from the detector.

What does the slope of a velocity-time graph represent?

Acceleration.

What is Acceleration?

How much an object’s speed changes in one second.

Which direction is acceleration when an object speeds up?

In the direction of motion.

Which direction is acceleration when an object slows down?

Opposite the direction of motion.

What is the acceleration rate for objects in free fall?

Gain or lose 10 m/s of speed every second.

When you have a forces problem do what

1.define positive direction

What is the distance equation for steady speed?

d = vt

What is the distance equation for starting from rest or stopping?

d = v²/2a OR d = ½at²

When is an object in Equilibrium?

If it is moving in a straight line at constant speed (or at rest).

What is the net force on an object in equilibrium?

Zero.

What is a Force?

A push or a pull that acts on an object.

What are the units of Force?

Newtons

What are the steps to solve equilibrium problems?

1. Draw a free-body diagram.

What must a free-body diagram include?

A labeled arrow for each force (pointing in direction of force) and a list of forces.

What is Mass?

How much material is contained in an object (kg).

What is Weight?

The force of a planet acting on an object.

What is the gravitational field strength on Earth?

10 N/kg (1 kg weighs 10 N).

What is Normal Force?

The force of a surface on an object in contact with it (acts perpendicular).

What does a platform scale read?

The Normal Force.

What is the x-component of a diagonal force (angle from horizontal)?

Force times cos θ

What is the y-component of a diagonal force (angle from horizontal)?

Force times sin θ

What is the Force of Friction?

Force of a surface on an object acting along the surface (opposite to motion).

What is the Coefficient of Friction (μ)?

A number that tells how sticky two surfaces are (not a force).

What is the equation for Force of Friction?

Ff = μFn

Incline Plane: What is the weight component parallel to the incline?

mg sinθ

Incline Plane: What is the weight component perpendicular to the incline?

mg cosθ

What is Newton's Second Law direction rule?

Acceleration (and net force) is in the direction of unbalanced forces.

What is the vertical acceleration of a projectile?

10 m/s per second.

What is the horizontal acceleration of a projectile?

Zero.

How do perpendicular velocities add?

Pythagorean theorem.

What is Newton's Third Law?

Force of Object A on B is equal to Force of Object B on A.

What is the acceleration of an object in circular motion?

v²/r (directed toward center).

What is the earth gravitational field

10N/kg or 1g/.1N

In a 2 body diagram one rope

One tension

In a 2 body diagram acceleration is

The same for each object

In a 2 body diagram write what sepreate for each

Both get Fnet=ma

Basic kinematic equation for constant acell and no delta x

Vf=Vo +at

Basic kinematic equation for constant acell and no final volume

Delta x=VoT+1/2at²

Basic kinematic equation for constant acell And no time

Vf²=Vo²+2a delta x

The static coefficient of friction is when an object is

Not sliding

The kinetic coefficient of friction is when an object is

Sliding

The static coefficient of friction could be

Any value

For 2 objects the maximum of static friction is greater than

The kinetic friction

How do massive objects attract

with a gravitational force.

What is the Universe gravitational constant

6.7 ×10^-11Nm²/kg²

What is the formula for gravitational force (Fo) between two objects?

Fg = ( G M1 M2)/d²

What is the gravitational field (g) near an object of mass (M)?

g = GMp/d^2, where d is the distance from the object's center.

How is the weight of an object near a planet calculated?

Weight = mg, where g is the gravitational field due to the planet at the object's location.

Is the gravitational field near a planet equal to the free-fall acceleration?

Yes, the gravitational field near a planet is always equal to the free-fall acceleration.

What is the value of the gravitational field on the Moon?

1.6 N/kg.

How is gravitational mass measured?

By measuring an object's weight using weight = mg.

How is inertial mass measured?

By measuring the net force on an object, measuring the object's acceleration, and using F net = ma.

What relationship has been found between gravitational mass and inertial mass?

In all experiments ever performed, gravitational mass is equal to inertial mass.

What is Momentum?

Momentum is equal to mass times velocity: p = mv.

When starting a momentum problem draw what?

Momentum bar chart

What are the standard units of momentum?

The standard units of momentum are newton seconds, abbreviated N's (equivalent to kg-m/s).

What is the direction of an object's momentum?

The direction of an object's momentum is always the same as its direction of motion.

What is the principle of conservation of momentum in collisions?

When no external forces act on a system of objects, the system's momentum cannot change.

How does total momentum behave before and after a collision?

The total momentum of two objects before a collision is equal to the objects' total momentum after the collision.

How is momentum characterized as a vector?

Momentum is a vector: total momentum of two objects moving in the same direction adds together; total momentum of two objects moving in opposite directions subtracts.

What does the center of mass obey?

A system's center of mass obeys Newton's second law: the velocity of the center of mass only changes when an external net force acts on the system.

How can impulse be calculated?

Impulse, J, can be calculated in two ways: 1. J = Δp (change in momentum) 2. J = Ft (force experienced multiplied by time).

What are the units of impulse?

Impulse has the same units as momentum, which are N's.

What does impulse represent on a graph?

Impulse is represented by the area under a force vs. time graph.

What are the units of all forms of energy?

All forms of energy have units of joules, abbreviated J.

What is the equation for Kinetic energy?

K = ½m v², where m is the mass of the object and v is its speed.

What is the equation for Gravitational potential energy?

Ug = mgh, where m is the mass of the object, g is the gravitational field strength, and h is the vertical height of the object above its lowest position.

What does the term mechanical energy refer to?

The sum of a system's kinetic and potential energy.

What is the equation for Spring potential energy?

U = ½kx, where k is the spring constant and x is the distance the spring is stretched or compressed from its equilibrium position.

What is Internal energy?

Heat energy that causes an increase in the temperature of the system.

What is the work-energy theorem equation?

Sum of all energy forms in position 1 + work done by external forces = sum of all energy in position 2.

What are the steps in the problem-solving process for work and energy?

1. Define the object or system being described. 2. Define the two positions you're considering. 3. Draw an annotated energy bar chart. 4. Write an equation based on the energy bar chart.

What is positive work?

Positive work is done by a force parallel to an object's displacement.

What is negative work?

Negative work is done by a force antiparallel to an object's displacement.

When is no work done by a force?

No work is done by a force acting perpendicular to an object's displacement.

What is the area under a force vs. displacement graph?

The area under a force vs. displacement graph represents work.

What is the equation for the force of a spring?

F = kx, where k is the spring constant and x is the distance the spring is stretched or compressed.

What are the standard units of the spring constant?

N/m.

What is the equation for the potential energy of a spring-earth-object system?

PE = ½kx, where x is measured from the position where the object would hang in equilibrium.