Simple Machines

Question 1

What are forces?

Answer 1

Push or pulls that can be balanced or unbalanced. If unbalanced, they can change the shape of objects and change the way they are moving.

Question 2

Name 6 simple machines.

Answer 2

Wheel and axel, lever, pulley, screw, wedge, inclined plane.

Question 3

What is work?

Answer 3

The transfer of energy caused by a force.

Question 4

Why do we need simple machines?

Answer 4

They make our work easier. We won’t need to use as much force with simple machines.

Question 5

What is a machine?

Answer 5

Instruments that reduce effort to do work.

Question 6

What is a pulley?

Answer 6

A rope that moves over a wheel.

Question 7

What forces in a pulley are always equal?

Answer 7

Upwards force = Downwards force

Question 8

What happens if you add more pulleys?

Answer 8

It decreases the amount of force needed to lift an object. However, the rope will need to be pulled further so the same amount of work is done.

Question 9

What are pulleys function?

Answer 9

Used to lift heavy objects.

Question 10

What are the three parts of a pulley?

Answer 10

Load, rope, and wheel.

Question 11

What is a lever?

Answer 11

A bar that balances on a fixed point and moves like a seesaw.

Question 12

What are other words to describe fixed point?

Answer 12

Fulcrum and pivot.

Question 13

What are the 2 main parts of a lever?

Answer 13

The bar and the fulcrum.

Question 14

What do you need to work a lever?

Answer 14

Bar, fulcrum, load, effort.

Question 15

What is load?

Answer 15

The object you’re lifting.

Question 16

What is force?

Answer 16

Effort applied to make an object move.

Question 17

What is effort?

Answer 17

Force applied to make an object move.

Question 18

What does a fulcrum do?

Answer 18

A fulcrum does not move and it provides support/balance to the bar.

Question 19

Explain how a see-saw works.

Answer 19

Your friend is sitting on one end (the load), and you are sitting on the other(the effort). You exert force on your end, trying to lift your friend off of the ground. When you push down on the seat, your effort lifts your friend up, while the fulcrum acts as the pivot, making the see-saw go up and down.

Question 20

Why is it easier to lift your friend up using a see-saw, rather than picking them up manually?

Answer 20

It’s easier to lift them up through the see-saw because less work is required to lift your friend.

Question 21

What happens if the length of the bar increases?

Answer 21

The effort needed decreases.

Question 22

Why do longer levers work better?

Answer 22

They allow a larger force to act upon the load than is supplied by the effort.

Question 23

What type of multipliers are levers?

Answer 23

Force multipliers.

Question 24

What is a force multiplier?

Answer 24

They reduce the amount of force needed to lift an object. Designed to produce increased forces.

Question 25

What is a distance multiplier?

Answer 25

Produce decreased forces but increase the distance an object moves.

Question 26

The law of conservation of energy?

Answer 26

The amount of work done by the lever cannot be greater than the work done by the pushing force.

Question 27

What is the wheel and axle?

Answer 27

Two or more wheels connected by an axel (spindle). The wheel turns with or around the axle.

Question 28

What is an example of a wheel and axel?

Answer 28

A wheelbarrow.

Question 29

What are wheelbarrows used for?

Answer 29

They are used by gardeners and builders to carry loads from place to place.

Question 30

How do wheelbarrows work?

Answer 30

When you lift the wheelbarrow, the handles move through a bigger distance than the load does.

Question 31

What is the calculation for W, F, and D?

Answer 31

``` W = F x D F = W/D D = W/F ```

Question 32

What are the units for W, F, and D?

Answer 32

``` W = J (Joules) F = N (Newtons) D= m (Meters) ```

Question 33

What are the calculations for W, MA, and F?

Answer 33

``` W = MA x F MA = W/F (how many pulleys there are) F = W/MA ```

Question 34

What are the calculations for ID and OD?

Answer 34

``` ID = OD x MA OD= ID/MA ```

Question 35

What is ID and OD?

Answer 35

``` ID = Input distance. Distance travelled by the rope. OD = Output distance. Distance travelled by the load. ```

Question 36

What is Potential Energy?

Answer 36

Energy due to height.

Question 37

What is the Calculation for P.E?

Answer 37

Mass x Gravity x Height

Question 38

What are the units for M, G, and H?

Answer 38

``` M = Kg G = 10 m/sec H = m ```

Question 39

Are moment and workdone the same?

Answer 39

Yes, except moment is calculated in Nm, while workdone is calculated in J.

Question 40

What is the formula for M, F, and D?

Answer 40

``` M = F x D F = M/D D = M/F ```