AP Physics 1 Review

What is position?

An object's location in space with respect to a specific frame of reference. Scalar, variable: x, units: m

What is displacement?

Change in position. Vector, variable: Δx, units: m

What is velocity?

The rate at which position changes. Vector, variable: v, units: m/s

What is speed?

The magnitude of velocity. Scalar, variable: |v|, units: m/s

What is acceleration?

The rate at which velocity changes. Vector, variable: a, units: m/s2

What is time?

The duration of observation. Scalar, variable: t, units: s

The slope in a position vs time graph is?

velocity

the slope of a velocity vs time graph is?

acceleration

The area under the graph in a velocity vs time graph is?

displacement

The area under the graph in an acceleration vs time graph is?

velocity

How do you set up a projectile motion problem?

Set up the equation for both x and y

What is mass?

The amount of matter or inertia in an object. Scalar, variable: m, units: kg

What is inertia?

An object's resistance to changes in motion. Scalar, variable: m, units: kg

What is force?

An individual push/pull interaction between two objects. Vector, variable: F, units: N ( = kg·m/s2)

What is net force?

The sum of all forces acting on an object. Vector, variable: ΣF, units: N

What is centripetal acceleration?

Acceleration, directed toward the center, for an object in circular motion. Vector, variable: aC, units: m/s2

What is newtons first law?

An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force.

What is newtons second law?

Force = mass x acceleration

What is newtons third law?

For every action there is an equal and opposite reaction

What is static friction?

Friction that acts on objects that are not moving

What is kinetic friction?

Friction between moving surfaces

What are the steps for solving a force problem?

1) Draw and label a free-body force diagram for each object

2) Set frames of reference (positive directions)

3) Break off-axis force vectors into components

4) Look for balance (Newton's First Law)

5) Where not balanced, use Newton's Second Law (ΣF = ma)

6) Substitute (values and/or other equations) and Solve

In circular motion net force is?

Unbalanced

In circular motion acceleration is?

Centripital

What is work?

The transfer of energy. Scalar, variable: W, units: J (= N·m)

What is energy?

The ability to do work. Scalar, variable: E, units: J

What is power?

The rate at which energy is transferred. Scalar, variable: P, units: W (= J/s)

What is Kinetic energy?

Energy of motion. Scalar, variable: K, units: J

What is gravitational potential energy?

Stored energy due to an object's vertical position. Scalar, variable: Ug, units: J

What is mechanical energy?

The sum of kinetic and potential energy. Scalar, variable: E, units: J

What are the three conservative forces?

gravitational, elastic & electric force

What is the equation for conservative forces?

WCON = ΔK = -ΔU

What is the equation for a non-conservative force?

WNC = ΔE

What is spring force?

The force exerted by a compressed or stretched spring (or other elastic material). Vector, variable: FS, units: N

What is displacement considering oscillations?

The distance a spring (or other elastic material) is compressed or stretched. Vector, variable: Δx, units: m

What is a Spring Constant?

The strength of a spring or elastic material. Scalar, variable: k, units: N/m

What is elastic potential energy?

Energy stored in a compressed or stretched spring. Scalar, variable: Us, units: J

What is simple harmonic motion (SHM)?

Oscillatory motion between two endpoints with no loss in mechanical energy

What is amplitude?

Maximum oscillation displacement from equilibrium. Scalar, variable: A, units: m

What is a period?

The amount of time to complete one cycle. Scalar, variable: T, units: s

What is frequency?

The amount of cycles per second. Scalar, variable: f, units: Hz (= cyc/s)

What is the midpoint of position? (SHM)

zero

What are the endpoints of position? (SHM)

max and min

What are the midpoints of velocity? (SHM)

max and min

What is the midpoint of velocity? (SHM)

zero

What is the midpoint of acceleration? (SHM)

zero

What are the endpoints of acceleration? (SHM)

max and min

What is the midpoint for net force? (SHM)

zero

What are the endpoints of net force? (SHM)

max and min

What is the midpoint of kinetic energy? (SHM)

max

What is the endpoint of kinetic energy? (SHM)

zero

What is the midpoint of potential energy? (SHM)

min

What is the endpoint of potential energy? (SHM)

max

How do you solve for position or velocity in simple harmonic motion?

Conservation of energy

In SHM where is velocity greatest?

Midpoint

In SHM where is period greatest?

endpoints

In SHM where is acceleration greatest?

endpoints

What is momentum?

Inertia in motion; the product of an object's mass and its velocity. Vector, variable: p, units: kg·m/s

What is impulse?

The product of a force acting on an object and the duration of that force, equal to the object's change in momentum. Vector, variable: J, units: N·s or kg·m/s

What is center of mass?

The weighted average location of all the mass in an object or system. Scalar, variable: xcm, units: m

In an elastic collision, what happens to kinetic energy?

It is conserved

In an inelastic collision, what happens to kinetic energy?

it is not conserved

In a completely inelastic collision what happens to kinetic energy?

It is not conserved

In an elastic collision what happens to the objects final velocities?

They are not equal (the objects do not stick together)

In an inelastic collision what happens to the objects final velocities?

They are not equal (the objects do not stick together)

In a completely inelastic collision what happens to the objects final velocities?

The are equal (the objects stick together)

What is the equation for the center of mass?

(mx+mx...)/m+m...

What is the equation for the velocity of center of mass?

mv+mv.../m+m...

What is the equation for the acceleration of center of mass?

ma+ma.../m+m...

What is Translational Motion?

Motion from one point in space to another

Examples: Straight-line motion, free fall, projectile motion, circular motion, oscillations, collisions, etc.

What is Rotational/Angular Motion?

Spinning motion about an axis. Sometimes the axis is through the object's center of mass; sometimes the axis doesn't pass through the object at all.

What is angular position?

An object's angular orientation with respect to a specific zero angle. Scalar, variable: θ, units: rad

What is angular displacement?

An object's change in angular position. Vector, variable: Δθ, units: rad

What is angular velocity?

The rate at which angular position changes. Vector, variable: ⍵, units: rad/s

What is angular speed?

the magnitude of angular velocity. Scalar, variable: |⍵|, units: rad/s

What is angular acceleration?

The rate at which angular velocity changes. Vector, variable: α, units: rad/s2

What is torque?

The product of a force and its distance applied from an object's axis of rotation. Vector, variable: τ, units: N⸱m

What is Static Equilibrium?

No motion; all forces and torques balance.

What is rotational inertia?

An object's resistance to changes in rotational motion, based on the object's mass, size, and shape, and the location of its axis of rotation. Scalar, variable: I, units: kg⸱m2

What is rotational kinetic energy?

Energy due to rotational motion. Scalar, variable: K, units: J

What is angular momentum?

The product of an object's rotational inertia and rotational velocity. Vector, variable: L, units: kg⸱m2/s

How do you transform between two motions?

Arc length s is equal to the radius r multiplied by the angle θ when it is measured in radians.

s = rθ

v = r⍵

a = rα

When is angular momentum maximized?

when the angle between r & p is 90°

What is the parallel axis theorem?

Used to find rotational inertia at an axis a distance d away from center of mass.

I′ = Icm + Md^2

What are the steps for solving rotational dynamics?

1) Draw and label a force diagram, indicating where forces act

2) Set axis of rotation and frame of reference (CW vs. CCW)

3) Write expressions for all nonzero torques

4) If static equilibrium, write balance equation for forces/torques

5) If rotating, Use Newton's Second Law (τNET = Iα)

6) Write expression for rotational inertia (see table on slide 8)