Simple Machines And Mechanisma

Question 1

What is a lever

Answer 1

A lever is a rigid bar that is supported at one point

Question 2

how is the classified

Answer 2

Classified by the locations of the fulcrum the input force and output source.

Question 3

What is the first class lever and give an example

Answer 3

Fulcrum between input force and output force, the output force is always in opposite direction to the input force. Ex.prying the lid off of a paint can

Question 4

What is the second class lever and give an example

Answer 4

Fulcrum at the very end and the output force between the input force and the fulcrum. The input force and output force are in the same direction. Ex. Wheelbarrow

Question 5

What is a third class lever and give an example

Answer 5

Fulcrum at one end the input force is in the middle and the output force is always less than the input force. The distance and speed at the output end of the lever are greater than at the input end. Ex.raking leaves, swinging a baseball hat or hockey stick

Question 6

How do u determine the mechanical advantage for a lever (IMA)

Answer 6

Divide the output force by the input force

Question 7

What is a pulley?

Answer 7

A pulley is made up of a grooved wheel with a rope or cable looped around it. A pulley can change the direction of a force or increase the output force depending on whether the pulley is fixed or movable

Question 8

What can fixed pulleys do?

Answer 8

Only change the direction of force. The output force is equal to the input force so it has an ideal mechanical advantage of 1.

Question 9

What happens if one end of the rope is fixed and the pulley is allowed to move For a lever?

Answer 9

You have a movable pulley

Question 10

What are the six simple machines

Answer 10

Lever, wheel and axe, pulley,inclined plane (ramp), screw snd wedge

Question 11

What is a wheel and axle and give an example

Answer 11

The wheel and axle is made of a shaft(axle) that is attached to a larger disk (wheel) ex.screwdriver, doorknob and bicycle wheels.

Question 12

What happens when and input force acts on a wheel? And provide an example

Answer 12

The output force provided by the axle produces and IMA greater than 1. Ex. Using a screwdriver to turn a screw

Question 13

How can u determine the IMA In a wheel and axle

Answer 13

When the input is applied to the wheel, the IMA can be determined by diving the radius of the wheel by the radius of the axle

Question 14

What happens when the input force is applied to the axle

Answer 14

The mechanical advantage is less than 1 since the input force is closer to the centre of the axle than the output force.

Question 15

What is an inclined plane

Answer 15

A sloping surface on which an object can move

Question 16

What does the ramp do?

Answer 16

The ramp increases the distance an object has to move, but reduces the force needed to move the object.

Question 17

How can the IMA be determined for a plane

Answer 17

The length divided by the height of the ramp

Question 18

What is a screw

Answer 18

Is an inclined plane wrapped around a rod.

Question 19

What is a thread

Answer 19

A continuous inclined plane, the length of the thread is longer than the length of the screw. This difference in length gives the screw it’s mechanical advantage. Also the thread allows it to penetrate into a hard surface

Question 20

What is a wedge and give an example

Answer 20

An inclined plane that travels through an object. The longer and narrower the Wedge, the greater it’s mechanical advantage. Ex. Needles, knives and your front teeth

Question 21

What is a mechanism and give examples

Answer 21

Two or more simple machines working together. Ex. Scissors are a mechanism since they are made of a lever and wedge

Question 22

What is efficiency

Answer 22

The efficiency of a machine measures the useful work done by the machine compared to the work needs to operate it.

Question 23

What happens when parts of a machine touch

Answer 23

Friction develops and transforms input energy into heat, therefore extra input force must be Put into the effort to make up for the energy lost to friction.

Question 24

Which machine had less friction (efficiency)

Answer 24

Highly efficient machines have less friction, and therefore produce less heat from friction and more input energy is transformed into output work

Question 25

How to u calculate efficiency

Answer 25

Useful output work(j) x 100 divided by input work