Projectile motion, work, energy, power, simple machines, gravitation

inverse square law

farther apart the objects get, the lower the force

acceleration of a projectile

9.8 m/s^2 towards the center of the earth

G=

6.67 x 10^-11

Inclined plans MA

MA≥1 (ED/LD)

parabola

the trajectory of the projectile since the velocity toward the surface of the earth constantly increases and the velocity parallel to the surface stays the same, the path followed by a projectile forms a shape called a PARABOLA

what is the use of fulcrum

to multiply forces

G is the _____

-the universal constant of gravitation -always equal to 6.67x10^-11 -

If MA equals one...

...it is not advantage of disadvantage

Horizontal motion is not affected by...

...vertical motion(vice versa)

more mass=

=more gravitational attraction

machine

A device used to multiply forces or to change the direction of forces. A machine can't put out more energy than is out in or create energy. It transfers energy from one place to another or transforms it from one form to another

Spring tide

A high or low tide that occurs when the sun, earth, and moon are all lined up. The tides due to the sun and moon coincide, making high tides higher than average and low tides lower than average. These tides occur at the times of full or new moons

lever

A simple machine of a bar that turns about a fixed point

vertical (y)

All right angles to a horizontal plane; in a direction, or having an alignment, such that the top is directly above the bottom

satellite

An object that falls around earth or some body rather than falling into it

pulley

Basically a kind of lever that can be used to change the direction of a force; exerted by a rope or a cable. A pulley or a system of pulley can multiply forces

Types of potential energy

Chemical Elastic: energy something had when stretched Gravitational: energy something has by virtue, falling Electrical: spark

Kinetic energy

Energy an object has when it's moving Moving fast= more kinetic energy Kinetic energy is directly proportional to an objects mass and the square of its speed ( twice as much mass= twice as much ke

Universal gravitational constant

G; physical constant that appears in the equation for newtons law of universal gravitation

Neap tide

If the moon is at a right angle, relative to the sun, the pulls are in different directions we get tides that are lower than average. high tides aren't as high and low tides aren't as low Half moon- waning crescent

Conservation of energy

If we add up all the energy in all the objects the total will always be the same before an interaction as it is after (PE at the top is transformed into KE at bottom; the energy transforms into another form of energy )

Planet

In the traditional model of solar systems, a celestial body larger than an asteroid or comet, illuminated by light from a star, such as the sun, around which it revolves

types of simple machines

Lever Pulley Inclined plane

component

One of the vectors, often mutually perpendicular, whose sum is a resultant vector. Any resultant vector may be regarded asthe combination of two or more components

horizontal (x)

Parallel to the plane of the horizon; at right angles to the vertical

Watt

SI unit of power; Joule per second. One watt of power is expended when one Joule of work is done in one second

Potential energy

Stored energy that can be used later (ask yourself: does it now have the potential to do something it couldn't do before)

KE at the bottom always equals...

The PE at the tkp

efficiency

The amount of work you et done for the amount of energy you use

Tide

The periodic variation in the surface level of the oceans and bays, caused by gravitational attraction of the moon and sun

work

The product of the net force on an object and the distance through which the object is moved (when force is constant and motion is in a straight line in the direction of the force) measured in Joules

energy

The property of an object or system that enables it to do work. Measures in Joules

Power

The rate at which work is done or energy is transferred. Equal to the work done or energy transferred divided by time measured in watts

Joule

The resulting unit of work; Newton meter, one joule of work is done when a force of one Newton is exerted on an object moved one meter in the direction of the force

In a closed system, what happens to the total energy

The total energy can't change, it cannot be increased or decreased

resultant

The vector sum of two or more component vectors

effort

a force that moves or attempts to move the lever

type 1 (lever class)

a lever that has the fulcrum in the middle MA or MD ex. seesaw

gravity

a mutual attraction between 2 objects that have mass

projectile

an object that moves without being influenced by forces other than gravity and air resistance

gravitation decreases rapidly

as the distance increases

how can we find speed at any point?

by resolving the x and y vectors using vector resolution *use the pythagorean theorem to figure out how fast an object is going

horizontal motion is a _____velocity

constant

what happens when you throw something straight up or straight down?

continue to accelerate at 9.8m/s^2

pulley system MA

depends on how many strands (ropes) are supporting the load -the more strands, the higher the MA pulleys have mechanical advantage

GPE

depends on the distance an object can

EPE

depends on the force used to stretch something and how far it's stretched

how is tension reduced

each strand has to support only a portion of the load if more than one)

type 3 (lever class)

effort in the middle MD only ex. baseball bat

type 2 (lever class)

has load in the middle MA only ex. wheelbarrow

horizontal velocity of a projectile (x)

if air resistance is neglected; horizontal velocity remains constant

what does the vertical (y) component do?

increases at 9.8 m/s^2 just like a free falling object

mechanical disadvantage

levers can reduce output forces if MA is less than 1 (less force output than input)

more force=

more acceleration

what 2 components does a projectile's velocity have?

the Vx is parallel to the ground the Vy is toward the ground

law of universal gravitation

the force of gravitation between 2 objects is directly proportional to their masses, and inversely proportional to the square of their distances. farther away you get=less force

load

the force that resists movement of a lever

mechanical advantage

the increase in force a lever provides it tells us how much force we can get out for the force we put in if MA is greater than 1 (more force output than input)

fulcrum

the pivot point on a lever