Physics - Work and Machines

What is work?

Force applied through a distance

What’s the unit for work?

Joules

What is needed for there to be work?

There has to be movement

What is a machine?

A device that changes the force and increases the motion

What are machines used for?

To make work easier and change it by doing it faster and with a lot of force if needed

What is the work formula for when force and motion are parallel?

W= f x d

What are simple machines?

A machine that has one function

What is a compound machine?

A machine that has 2 or more functions

What happens when the force and the motion of an object are perpendicular?

The work of that force equals zero.

What happens when the angle between force and motion is not parallel or perpendicular?

The work done is less than the force multiplied by distance but more than zero

What are the six types of simple machines?

Lever, pulley, wheel and axle, inclined plane, screw, and wedge

What is an example of a compound machines and why?

A pair of scissors. It combines two wedges and two levers

Can machines increase force and speed at the same time?

No, it can only be force or speed

What is the amount that goes out of a machine?

Is the same as the amount of work that got in the machine

What is efficiency?

The ratio of output work and input work

How is efficiency measured?

In percent

What can make machines more efficient and why?

Reducing friction because friction wears down the material

What is the efficiency formula?

Efficiency= output work/input work x 100

What is mechanical advantage?

The ratio of output force to input force

What is the mechanical advantage formula?

MA= output force/input force

What does mechanical advantage describe?

The effectiveness of a machine at increasing force.