Simple Machines

Question 1

What is a machine?

Answer 1

A device with which work may be accomplished.

Question 2

What are the 5 purposes of machines?

Answer 2

• Transform energy
• Transfer energy
• Multiply force
• Multiply speed
• Change direction

Question 3

Name the 6 simple machines.

Answer 3

• Lever
• Pulley
• Wheel and axle
• Gear
• Inclined plane
• Screw

Question 4

What is mechanical advantage?

Answer 4

A comparison of the output force to the input force or output distance to the input distance.

Question 5

True or False: You can gain speed and force simultaneously with machines.

Answer 5

False

Question 6

What is the fulcrum in a lever?

Answer 6

The pivot point.

Question 7

In a first class lever, where is the fulcrum located?

Answer 7

Between the effort and the resistance.

Question 8

Give an example of a first class lever.

Answer 8

Seesaw

Question 9

What is the relationship between force and distance in a first class lever?

Answer 9

You can gain force or distance but not both at once.

Question 10

In a second class lever, where is the fulcrum located?

Answer 10

At one end, with the effort applied at the other end.

Question 11

Give an example of a second class lever.

Answer 11

Wheelbarrow

Question 12

What is the advantage of a second class lever?

Answer 12

You can only gain force.

Question 13

In a third class lever, where is the fulcrum located?

Answer 13

At one end, with the resistance at the other and the effort between them.

Question 14

Give an example of a third class lever.

Answer 14

Retractable landing gear on an aircraft.

Question 15

What is the primary purpose of a single fixed pulley?

Answer 15

To change the direction of the force.

Question 16

What is the mechanical advantage of a single movable pulley?

Answer 16

2

Question 17

What determines the mechanical advantage of a block and tackle?

Answer 17

The number of weight supporting ropes.

Question 18

What is the mechanical advantage of a block and tackle with four pulleys?

Answer 18

4

Question 19

What is the relationship between the drive gear and driven gear in a gear system?

Answer 19

The drive gear provides the input force, while the driven gear receives the force.

Question 20

What is the mechanical advantage when the diameter of the driven gear is smaller than that of the drive gear?

Answer 20

Less force out than force in.

Question 21

What is the mechanical advantage of a worm gear?

Answer 21

Equal to the number of teeth on the spur gear.

Question 22

What is an inclined plane?

Answer 22

A simple machine that facilitates raising or lowering heavy objects by applying a small force over a long distance.

Question 23

Fill in the blank: A bolt operates on the principle of an _______.

Answer 23

Inclined plane

Question 24

What is the mechanical advantage of a fine threaded bolt compared to a coarse threaded bolt?

Answer 24

Greater mechanical advantage due to more threads per inch.

Question 25

What does a chisel exemplify in terms of simple machines?

Answer 25

Wedge

Question 26

How is mechanical advantage calculated for an inclined plane?

Answer 26

Length of incline divided by the height of the incline.

Question 27

Mechanical Advantage =

Answer 27

Force out / Force in =
Distance out / Distance in

Question 28

What is the Equation for levers?

Answer 28

fe x de = fl x dl

fe = effort
de = distance from fulcrum
fl = load (weight)
dl = distance from load to fulcrum

Question 29

Which simple machines operate off the principle of a lever?

Answer 29

lever
pully
wheel and axle
gear

Question 30

Which simple machine operate off the inclined plane principle?

Answer 30

Inclined plane
screw