Science FInal Study Guide

What is the average speed of a car traveling 100 kilometers in 25 minutes?

4km/m

A racecar travels 2000 meters in 20 seconds. What is the racecar’s average speed?

100m/s

A plane traveled for about 2.5 hours at a speed of 1200km/hr. What distance did it travel?

3000km

What makes an object a good reference point for describing motion?

Something that does not move in reference to the object you are measuring

What is the term used to describe speed in a given direction?

Velocity

What is the term used to describe the rate at which velocity changes?

Acceleration

When objects slow down, are they accelerating? Why or why not

Yes, because its a change in speed or direction (deceleration)

Is a car driving at a constant speed of 10km/hr accelerating? Why or why not?

No, because the speed is constant at 10km/hr so it s not accelerating

Newton’s First Law of Motion

An object at rest will remain at rest unless acted upon by a nonzero net force

EX: Skateboard being stopped by a wall

Newton’s Second Law of Motion

An object’s acceleration depends on its mass and on the net force acting on it

EX: Adding dogs to a sled to increase its acceleration

Newton’s Third Law of Motion

If one object exerts a force on another object, the object exerts equal force in the opposite direction on the first object

EX: Swimmer in a pool

Law of Conservation of Momentum

In the absence of outside forces like friction, the total momentum of objects that interact don’t change

What is the difference between a balanced and an unbalanced force?

Balanced: Net force=0N

Unbalanced: Unequal force/causes movement

Sliding Friction

Occurs when 2 solid surfaces slide over each other

EX: Penguin on ice

Static Friction

Acts between objects that aren’t moving

EX: Pushing a couch across a roo

Fluid Friction

When a solid object moves through a fluid

EX: Animal swimming in water

Rolling Friction

When an object rolls across a surface

EX: Bike on a sidewalk

______is a resistance to motion.

Inertia

The force of gravity on a person or object on the surface of a planet is called_____.

Weight

_______describes how much matter is in a given volume.

Mass

Energy is the ability to do work or cause_______.

Change

Kinetic Energy

The energy an object has due to its motion

EX: A bowling ball has a greater mass so it has greater energy

Potential Energy

Energy that results from the position or shape of an object

EX: Winding a toy

Elastic Energy

Energy associated with objects that can be compressed or stretched

EX: Trampoline

Nuclear Energy

Type of PE stored in the nucleus of an atom

EX: Nuclear power plant

What materials are good conductors of electricity? Good insulators?

Conductors: Metals (silver)

Insulators: Rubber, glass, and wood

What is the difference between a series and a parallel circuit?

Series: Has one path, so if one light goes out all the other ones go out

Parallel: Has multiple paths for energy to flow through so if one light goes out, energy can still keep other lights lit up

An unbroken path through which electric charges can flow is called a ______.

Electric circuit

What completes the path of a current in a circuit?

A closed conductive path

What determines the resistance of a wire?

Material, diameter, length, and temperature

What happens when more branches are added to a parallel circuit? What happens when more branches are added to a series circuit?

Parallel: resistance decreases, current increases

Series: gets dimmer

Energy is always_______in a circuit.

Conserved

Every magnet, regardless of its shape, has two_____.

Magnetic poles

The motion of liquid____in Earth’s outer core creates a magnetic field.

Iron

How does a compass work?

A compass is a device that has a magnetized needle that can spin freely.

What is the difference between the Earth’s magnetic poles and geographic poles?

Geographic poles are fixed points at N/S where the axis of rotation meets the surface, while magnetic poles are shifting locations where the planet’s magnetic field lines are vertical. They are not at the same location.

What creates mechanical waves?

A source of energy causes a medium to vibrate.

Which parts of a longitudinal wave are compressions? Which are rarefactions?

Compression: Closer together

Rarefaction: Farther apart

Label the parts of the wave.

Highest part: Crest

Lowest: Trough

Length between crests: Wavelength

Length between crests and the medium: Amplitude

How often a wave occurs is a wave’s______.

Frequency

How does a transverse wave move in a medium?

At a 90 degree angle

Ocean waves are an example of______.

Surface waves

Reflection

The bouncing back of an object or wave when it hits a surface it cannot pass through

EX: Mirror

Refraction

The bending of waves as they enter a new medium at an angle, caused by a change in speed.

EX: Putting a pencil in a cup of water

Interference

Interaction between waves that meet

EX: Constructive/Deconstructive interference

Resonance

The increase in the amplitude of a vibration when external vibrations match an objects’ natural frequency

EX: Falling bridge

The less energy a wave has, the smaller its______.

Amplitude

Energy can be neither destroyed nor______.

Created

How do sound waves move?

They move by vibrating the particles in a medium.

Sound travels as a_____.

Longitudinal wave

The_____of sound depends on the temperature, elasticity, and density of the medium through which the sound travels through.

Speed

What is the difference between how sound travels through a warm and cold temperatures?

Warmer=faster

Cooler=slower

Sound waves with frequencies above the normal range of human hearing are called_____.

Ultrasound

What property/properties of a sound depend on the energy and intensity of the sound waves?

Loudness

What are electromagnetic waves?

An electromagnetic wave is a transverse wave made up of vibrating electric and magnetic fields that move through space or some medium at the speed of light

Light that causes an electron to move so much that it is knocked out of a metal is called the_______effect.

Photoelectric

Be able to label the parts of the electromagnetic spectrum.

Radio waves

Microwaves

Infrared waves

Visible light (ROYGBIV)

Ultra-violet waves

X-rays

Gamma rays

High____= Low______

Low_____= High_____

High frequency = Low wavelength

Low Frequency = High wavelength

List a common use of each wave on the electromagnetic spectrum

Radio: radio programs

Microwave: phone communication

Infrared: heat lamps

Visible light: rainbow

Ultraviolet: produces vitamin D

X-rays: makes images of bones and teeth

Gamma rays: examines body’s internal structures

What does a thermogram record?

Images of infrared radiation emitted by an object

How does a radar work?

Uses reflected microwaves to detect objects and measure their distance and speed

What is the difference between AM and FM radio waves?

AM stations use kilohertz (kHz) and FM stations megahertz (MHz)

A material that reflects or absorbs all the light that strikes it is_____.

Opague

Force

Unit of measurement: Newtons

Formula: F = m x a

Frequency

Unit of measurement: Hz

Formula: not needed

Acceleration

Unit of measurement: m/s squared

Formula: A = Vf - Vi divided by T

Speed

Unit of measurement: m/s

Formula: S = d/t

Distance

Unit of measurement: m

Formula: D = s x t

Slope

Formula: Rise/Run

Resistance in a circuit

Formula: R = voltage/current

Energy/Work

Unit of measurement: Joules

Formula: W = f(d)

Time

Unit of measurement: varies

Formula: Final Speed-Initial Speed divided by Acceleration

GPE

Unit of measurement: Joules

Formula: weight x height

Velocity

Unit of measurement: m/s (direction)

Formula: V = displacement/time

Wave speed

Unit of measurement: Hz

Formula: V = f x w