Systems 3/4 - Mechanical

Units - what is the measurement (from the calculation sheet) and base units name?

1. d / m (answer: distance in meters)

2. F / N

3. T / Nm (like a backwards J)

4. P / Pa

5. W (or E) / J

6. t / s OR m

1. distance in meters

2. Force in Newtons

3. Torque in NewtonMeters

4. Pressure in Pascals

5. Work (or Energy) in Joules

6. time in seconds OR minutes (speed is best in m/s)

Force

1. What equation should you use?

2. Calculate the answer from the image

1. F = m x a

(rare)
What’s the easy way to convert:

1. From km/h to m/s

2. From m/s to km/h

1. Divide by 3.6

2. Multiply by 3.6

Inclined Planes

The best formula for inclined planes is not provided (it is indirectly)

1. What is the better formula?

2. Calculate the answer from the image

Answer on the back.

1. Effort (Force in N) = H/S x load (Force in N)
   (Derived from the mechanical advantage equation)

(rare)
Screw

1. What part of a screw equates to the slope?

2. What part of a screw equates to the height?

1. The pitch, or distance between the peaks of the screw

2. The circumference of the screw

4 types of motion

1. What are their names, with one example

2. Draw/show arrows to match each one (image)

1. Linear, train moving on tracks

2. Rotary, wheels on a car

3. Reciprocating, a piston

4. Oscillating, a swing

3 Types of springs

Name each one

1. Torsion spring

2. Compression spring

3. Tension spring

5 common forces (In Systems exams)

Name + Describe each + example (image)

1. Torsion - twisting force

2. Compression - squishing

3. Tension - pulling apart

4. Shear - cutting or splitting

5. Friction - limiting force from contact

Potential energy types

1. Description

2. Type 1

3. Type 2

4. Type 3

(exam usually gives you some of this info for you to fill out rest)

1. Any energy type that has “stored” energy

2. Gravity (water at the top of a dam)

3. Elastic (stretched spring)

4. Chemical (battery storage)

3 common (non-potential) energy types

Name + describe each + example (image)

(exam usually gives you some of this info for you to fill out rest)

1. Kinetic/ mechanical, physical movement, propeller

2. Electrical, energy in wires, circuits

3. Radiant/ thermal, light, infrared, heat (typically from friction)

Ratchet and Pawl

1. Description

2. Example

3. Identification (image)

1. Used to limit rotary motion to one direction

2. Ratchet Wrench

Rack and Pinion

1. Description

2. Example

3. Identification (image)

1. A gear (pinion) meshed with a flat set of teeth (rack). Motion transformation is rotation to linear.

2. Steering in cars

Cam and follower

1. Description

2. Example

3. (rare) Description of a wedge cam

4. Identification (both kinds) (image)

1. A rotating plate (many shapes) that transforms to a reciprocating follower

2. Camshaft and intake valve

3. A reciprocating or linear wedge that transforms to a reciprocating follower

Piston and crank

1. Description

2. Example

3. Identification (image)

1. A reciprocating piston that transforms to a rotating crank(shaft)

2. An engine (chemical > mechanical energy > transformation)

(rare)
Universal Joint

1. Description

2. Example

3. Identification (image)

1. A rotating yoke (end of an axel), which though a cross rotates another yoke/ axel in a different direction/ angle

2. Rear-wheel drive cars

Pulleys
The best formula pulleys is not provided (it is indirectly)

1. How many falls are there?

2. How do you calculate the MA?

3. Calculate the answer from the image

1. Falls = the number of ropes/wires extending away from the moving pulley = 3.

2. Load / Falls = Effort

Gear Physics

1. What does MA, VR and GR stand for?

2. MA is a change in…?

3. VR is a change in…?

4. Ignoring losses, how do MA and VR relate?

5. Ignoring losses, how do GR and MA relate?

1. Mechanical Advantage, Velocity Ratio, Gear Ratio

2. A change in force

3. A change in distance travelled (or speed)

4. Inversely proportional (eg. MA=1/4, VR = 4/1)

5. Equal (eg. GR = 1/4, MA = 1/4)

Gear Physics Continued

1. What can Teeth of a driver be used to first calculate?

2. What can Diameter of a driver be used to first calculate?

3. Would the Pulley ratio and Gear ratio of a toothed belt be equivilent?

1. GR for teeth

2. Pulley Ratio

3. Yes

Chain and Sprocket

1. Describe the motion transformation

2. Pros/ Cons (instead of a belt)

3. What feature is used to calculate MA?

4. Use case?

5. Identification (image)

1. Transfers the same direction of rotation over a distance

2. Won’t slip, doesn’t get brittle over time/ More parts, more maintenance, more noise

3. The ratio of teeth OR diameter of the driven gear over the driver gear

4. A bike

Belted Pulley

1. Description

2. Pros/ Cons (instead of a chain)

3. What feature is used to calculate MA?

4. Use case?

5. Identification (image)

1. A typically rubber belt that transfers the same direction of rotation over a distance

2. Cheaper/ can slip

3. The ratio of diameters of the driven pulley over the driver pulley

4. Drill press

Toothed Belt

1. Description

2. Pros/Cons to belts and chains?

3. What feature is used to calculate MA?

4. Use case?

5. Identification (image)

1. A typically rubber belt with teeth that transfers the same direction of rotation over a distance

2. Reduces slipping of a belt, but is cheaper and simpler than a chain/ can still loosen over time

3. The ratio of teeth OR diameter of the driven gear over the driver gear

4. 3D printer

Name these gears 1-9

1. Spur gear

2. Bevel gear (not always 90° angle)

3. Helical gear (V shaped teeth = herringbone)

4. Crown gear

5. Worm gear

6. Rack and pinion

7. Idler gear

8. Driver gear

9. Driven gear

Does an idler effect MA or VR?

No

Compound Gears

1. How do you combine two GRs for total GR?

2. What does that mean the MA and VR will be?

3. Calculate the answer from the image

1. Multiply each GR together (Driven teeth/Driver teeth)

2. GR = MA, VR is inversely proportional (excluding losses)

3. GR = 6/1, MA = 6/1, VR = 1/6

Levers

1. What are the 3 types

2. What are their arrangement

3. An example

1. First class - EFL - Effort, Fulcrum, Load - See-saw, Boom gate

2. Second class - ELF - Effort, Load, Fulcrum - Wheelbarrow, Nail clipper

3. Third class - FEL - Fulcrum, Effort, Load - Fishing rod, Baseball bat

Torque in equilibrium

1. How could you modify T = F x d for this example question?

2. Could the same equation be used if the crane diagram is replaced by a diagram of two differently sized wheels?

3. Calculate the answer from the image

1. F1 / d1 = F2 / d2 (because torque is equal for both sides/ same pivot point)

2. Yes

General Compounded Systems

1. If there is a pulley attached to a gear ratio, do you multiply them together?

2. If there are simple mechanisms in the compound that do not have a MA or VR (1:1), what do you do?

3. Calculate the answer from the image

1. Yes

2. Ignore (multiply the ratio by 1)

Hydraulic Systems

1. What happens to pressure in an ideal hydraulic system?

2. How could you modify P = F/A for this example question? (Calculate the answer)

1. Pressure is equal in whole system

2. F1 / A1 = F2 / A2 (because pressure is equal to both sides)

(rare)
Movement in Hydraulic Systems

1. If the piston B moves down 9m, what equation could we use to find the change in height for piston A?

2. If there are air bubbles, what changes?

1. Work (from W = F x d) stays equal in whole system too, so F1 x d1 = F2 x d2

2. The liquid could compress and the system becomes spongy

John has 3 apples, but his train is 7 minutes late.

Calculate the mass of the sun

Honestly it was just bothering me that there was 29 mechanical flashcards

A: 1.99 × 10³⁰ kilograms