Machines help you do work by??

Question

Do machines help you work by decreasing the amount of work that must be done , changing the size or direction of a force , decreasing friction or conserving energy?

Answer 1

Only one answer here. Machines help by changing the size or direction of a force.

Think of a lever, the most basic machine...

Work is Force x Distance. When you use a lever, you move a larger distance, but with less force. The thing you are lifting moves a little, but is very heavy. Force and distance "cancel each other out". So answer #1 isn't right.

Decreasing friction. Nope. A lever, pulley, or other machine doesn't decrease friction. It may make the force of friction seem less, because you are using less force over a longer distance. Answer #3 isn't right.

Conserving energy: All things conserve energy (meaning 100% of the energy put in comes out in the end), even if they aren't efficient (for example, a light bulb doesn't use 100% of the electricity as light, but it gives off heat, too!) This is important, but it doesn't help you do work. Answer #4 isn't right.

Answer #2 is correct. Machines can change a force, by amount (like a lever or pulley, which can help you lift heavy things with less force) or changing direction (pushing down on a lever moves something else up).

Answer 2

Machines, as good as they are, cannot decrease the amount of work to be done. It may ease the amount of work you personally have to perform, but the amount of work will remain the same.
The answer is changing the size or direction of a force - examples are levers and pulleys.
Obviously, all machines must conserve the energy - even if it is wasted in heat or friction.

Answer 3

All of the above.


Machine
From Wikipedia, the free encyclopedia
Jump to: navigation, search
This article is about devices that perform tasks. For other uses, see Machine (disambiguation).

Wind turbinesA machine is any mechanical or organic device that transmits or modifies energy to perform or assist in the performance of tasks. It normally requires some energy source ("input") and accomplishes some sort of work.

People have used mechanisms and machines to amplify their abilities since before written records were available. Generally these devices decrease the amount of force required to do a given amount of work, alter the direction of the force, or transform one form of motion or energy into another.

The mechanical advantage of a simple machine is the ratio between the force it exerts on the load and the input force applied. This does not entirely describe the machine's performance, as force is required to overcome friction as well. The mechanical efficiency of a machine is the ratio of the actual mechanical advantage (AMA) to the ideal mechanical advantage (IMA). Functioning physical machines are always less than 100% efficient.

Modern power tools, automated machine tools, and human-operated power machinery complicate the definition of "machine" greatly. Machines used to transform heat or other energy into mechanical energy are known as engines.

Hydraulics devices may also be used to support industrial applications namely, heavy equipment industries, automobile industries, marine industries, aeronautical industries, construction equipment industries, earthmoving equipment industries.

Answer 4

The answer is yes. A machine could do any or all of the above.

Answer 5

Machines help you by all of the ways that you mentioned above.