Semester 1 Physics Honors Concepts

The Scientific Method

A systematic approach used in scientific inquiry to investigate phenomena, acquire new knowledge, or correct and integrate previous knowledge

Steps of the Scientific Method

1. Make Observations

2. Question and form a hypothesis

3. Formulate controlled experiments to test your hypothesis wrong

4. Interpret Results and tweak hypothesis if needed

5. Form conclusions

Model

A tool to describe phenomena

What do SI units describe?

Units that describe a single dimension

What are the main 3 SI units?

meters, kilograms, seconds

Derived Units

Units that are made by combining SI units through multiplication and division (ex. velocity=m/s)

Accuracy

How close a measurement is to the goal

Precision

How exact the measurement is (ex. Significant Figures)

What is the point of tables, graphs, and equations?

To make understanding data easier to understand

What do equations do?

Describe measured or predicted relationships between physical quantities

Frame of reference

A specific point set to determine the precise location of subjects in space and time

Displacement

The change in position (not necessarily distance)

What is the SI unit for displacements?

Meters

When is displacement negative?

When the object has moved from right to left

Average velocity

the total displacement divided by the time interview that the displacement occured

What is the SI unit for velocity?

m/s

What is the difference between speed and velocity?

speed is only one direction, it has no magnitude. Whereas velocity is a vector quantity

Average Speed

distance/time

What is the velocity for object 1?

Positive velocity

What are the equations used for anything with constant acceleration?

Kinematic Equations

What is the velocity of object 2?

0 velocity

What is the velocity of object 3?

negative velocity

What is instantaneous velocity?

The velocity of an object at some instant or at a specific point in the objects path.

Acceleration

the rate at which velocity changes over time

When does an object accelerate?

When its speed, direction, or both changeT

T/F Acceleration is a scalar quantity?

False

What’s the acceleration at point A?

acceleration is positive

What’s the acceleration at point B

There is no acceleration

What’s the acceleration at point C

The acceleration is negative

When is acceleration constant?

When velocity is changing by the same amount during each time interval.

What is free-fall?

the motion of a body when only the force due to gravity is acting on the body

What is the acceleration of an object in free-fall called?

acceleration due to gravity or free-fall acceleration

What is g equal to?

g=9.81

Why is it typically used as -9.81 m/s²?

Because objects in free-fall fall towards the earth

What is a scalar?

A physical quantity that has magnitude but no direction

What is a vector?

A physical quantity that has both magnitudde and direction

What is a resultant?

The sum of two ow more vectors.

How should you draw a vector?

Start at the tail and then finish at the tip ——>

T/F A vector needs to be added from greatest to least?

False

T/F you can add the opposite to subtract a vector?

True

What happens when you multiply or divide a vector by scalars?

Results in vectors.

When do you use the pythagorean theorm?

To find the magnitude of the resultant vector on a right triangle

When do you use the tangent function?

To find the direction of the resultant vector

Why do you break a vector into two components?

You can more easily describe an objects motion

What are the Sine and Cosine functions used for?

To find the components of a vector

What is a projectile?

Any object thrown or launched into the air

What shape does a projectile make?

Curved/ parabolic

Which ball will land first?

They will fall at the same time

How can you use kinematics for projectiles?

You can resolve the vectors into components first, then use kinematics

What is a force?

An action exerted on an object which may change the objects state of rest or motion

What is the SI unit for force?

Newton (N) Kg(m/s²)

How can forces act through?

Both contact and at a distance

T/F force is a vector quantity

True

What is a diagram that shows force vectors as arrows called?

Force Diagram

What is a force diagram that only shows the forces acting on a single object called?

free-body diagram

What is Newtons first law?

objects at rest stay at rest, and objects in motion will stay in motion UNLESS the object experiences a net external force

What is the net force?

The vector sum of all forces acting on an object.

What is inertia?

the tendency of an object to resist being moved or if the object is moving, resist a change in speed or direction

What is a measure of Inertia?

Mass

What is equillibrium?

the state in which the net force is 0.

What is Newtons second law?

the acceleration of an object is directly proportional to the net force acting on the object and inversely proportional to the object’s mass

Whats the equation for Net Force?

EF=ma

What is Newtons third law?

For every action, there is an equal and opposite reaction

What is weight?

the magnitude quantity of Fg

How do you calculate weight?

Fg=mag

What is normal force?

the force that acts on a surface in a direction perpendicular to the surface

What is kinetic Friction

The force that opposes the movement of two surfaces that are in contact and are sliding over each other

What is static friction?

a force that resists the initiation of sliding motion between two surfaces

T/F Kinetic friction is always more than the maximum static friction

False

On a free body diagram, what direction is friction?

Always parallel to the surface of the object, kinetic friction is always opposite to the direction of motion

How do you determine the direction of static friction

Use the principle of equillibrium

What is the coefficient of friction?

the quantity that expresses the depedence of frictional forces on the particular surface

How do you find the coefficient of kinetic friction?

uk=Fk/Fn

How do you find the coefficient of static friction?

us=Fsmax/Fn

T/F air resistance is a form of friction

true

What is terminal speed?

when an object reaches a constant maximum speed during free-fall

What are the 4 fundamental forces?

electromagnetic,gravitational, strong nuclear, weak nuclear

What is work?

done on an object when a force causes displacement of the object

T/F Work is only done when components of a force are parallel to a displacement

True

What is kinetic energy?

the energy of an object that is due to the object’s motion

What is the equation for Kinetic Energy?

KE=(1/2)mv²

What is the work-kinetic energy theorm?

the net work done by all the forces acting on an object is equal to the change in the object’s kinetic energy

What is Potential Energy?

the energy associated with an object because of the position, shape, or condition of the object

What is gravitational potential energy?

the potential energy stored in the gravitational fields interacting bodies

How do you find PEg?

PEg=mgh

what is elastic potential energy?

the energy available for use when a deformed elastic object returns to its original configuartion

How do you find PEelastic?

PEelastic=1/2kx²

What is “k” in PEelastic?

the spring constant

What does it mean to be conserved?

to remain constant

What is mechanical energy?

The sum of kinetic energy and all forms of potential energy associated with an object or group of objects

How do you find ME?

ME=KE=EPE-(Fk+Fs)

What is power?

a quantity that measure the rate at which work is done or energy is transformed

What are the two equations for power?

P=W/t or P=Fv

In 250 BC, how did a philospher come to the conclusion that the earth was curved?

He measure the angles of the sun in Egypt and Greece and his calculations pointed to a curved earth.

Who was the scientists who believed the moon landing was fake?

Bill Kasing

Who pointed out NASA’s control of video and audio footage?

Bart Suprell

What is a special revelation?

The Bible, given to a set group of people

What is a general revelation?

The world, something everyone can see

What is theism?

a belief in God/god

What is Atheism?

A belief in no God/god