Quarter 2

work

Work is the transfer of energy that occurs when a force is applied over a distance.

unit work

Joule

energy

• is the fundamental ability to do work or cause a change. It is a conserved quantity that can be stored and transferred in various forms (e.g., kinetic, potential, thermal). 

power

is the measure of how fast energy is transferred or how quickly work is done, defined as work divided by time. Power is measured in watts.

what is the formula for power

power equals work divided by time

how did the term horsepower come about

The term "horsepower" was developed by Scottish engineer James Watt in the late 18th century

horespower

horsepower (hp) is a unit of power defined a measure of the rate at which work is performed. 

how is it used today

"horsepower" is a common measure of the output power of various engines and motors, including those in cars, motorcycles, HVAC units, lawnmowers, and railway locomotives.

• What are simple machines?

Simple machines are basic mechanical devices with few or no moving parts that modify motion and the magnitude or direction of a force to perform work. They use mechanical advantage or leverage to multiply force, making tasks easier to perform. 

• What are the two main categories of simple machines?

levers and inclined planes.

• What is mechanical advantage?

Mechanical advantage is the number of times a machine multiplies an applied input force.

Describe gears and hydraulics.

Gears are sometimes included as simple machines and use different sizes and arrangements to achieve a distance or force advantage. 

Hydraulics is a field of science dealing with the practical application of liquids in motion.

what is a lever

A simple machine
An object that pivots around a fixed point called a fulcrum, used to apply a force to a load.

what are the 3 levers

• First-class: Fulcrum is between the effort and the load (e.g., seesaw, crowbar).

• Second-class: Load is between the fulcrum and the effort (e.g., wheelbarrow, nutcracker).

• Third-class: Effort is between the fulcrum and the load (e.g., tweezers, fishing rod).

what is static equilibrium

state of balance
A condition where an object is at rest, and all the forces and torques acting upon it are balanced, resulting in a net force and net torque of zero.

what is an inclined plane

An inclined plane is a simple machine consisting of a flat surface tilted at an angle to the horizontal, used to move objects to a higher or lower level with less force than lifting them vertically. 

how to calculate MA

The mechanical advantage (MA) of an ideal inclined plane is calculated by dividing the length of the inclined surface (the distance over which the force is applied) by the vertical height it rises. The formula is

MA=LengthHeightbold cap M bold cap A equals the fraction with numerator Length and denominator Height end-fraction

𝐌𝐀=Length over Height

What is a wedge?

A wedge is a simple machine that is essentially a portable inclined plane, or two inclined planes joined back-to-back. It is used to separate two objects or portions of an object, lift an object, or hold an object in place.

screw

A screw is a fastener that features an external helical ridge known as a thread, which is wrapped around a cylindrical shaft. This thread is designed to mate with a corresponding internal thread in a pre-drilled hole or nut, converting rotational motion into linear motion and holding materials together.

What do a screw's threads have to do with its strength and why?

A screw's threads significantly impact its strength, primarily its tensile strength and shear resistance.