Simple Machines
Describe the motion of a piston head in a combustion engine.
Reciprocal motion.
An elevator starts at rest and accelerates upwards at a constant rate until it reaches 10 m/s. The mass of the elevator and occupants is 2500 kg. The tension on the elevator cable is 30 000 N. Determine the distance the elevator travels during acceleration.
22.77 m [difference in force, acceleration, SUVAT]
Pearlite is composed of alternating layers of...
Ferrite (alpha) and Cementite (Fe3C)
What are 2 properties of Ultra-High Carbon Steel
[2 from the following] Wear and Abrasion Resistance, Hard, high Tensile & Yield Strength, Low Ductility
SEE IMAGE (Q5 2024)
A
A construction worker uses an inclined plane (ramp) to move a heavy load onto a raised platform.
Identify one disadvantage of using an inclined plane instead of lifting the load vertically
An inclined plane requires the load to travel a greater distance compared to lifting it vertically.
A maintenance trolley, weighed 85kg, is released from rest on a warehouse loading ramp inclined at 22 degrees. The coefficient of kinetic friction between the trolley wheels and the ramp surface is 0.18. Calculate the acceleration of the trolley as it slides down the ramp.
1.9 m/s2
This boundary line separates a single-phase solid region from a two-phase solid region, marking the limits of solid solubility.
Solvus Line
You need a material for high-strength, heavy-duty industrial power transmission gears that operate at high speeds. The gears must withstand intense tooth-to-tooth friction, but they cannot use any oil or grease because they operate in a sterile cleanroom environment
Nylon
SEE IMAGE (Q3 2023)
A
A student uses a ramp to push a 200 N box into the back of a truck. The ramp is 2.5 m long and the truck is 0.5 m high. Calculate the mechanical advantage of the ramp
MA= 2.5/0.5= 5
A 45kg crate is positioned at the top of a delivery ramp inclined at an angle of 25 degrees. The ramp provides a constant kinetic frictional force of 62.0 N opposing the motion. The crate is released from rest and slides down 6.5m.
Determine the final velocity of the delivery crate as it reaches the bottom of the ramp.
The final velocity of the delivery crate at the bottom of the ramp is 5.99 m s⁻¹
What is the specific name given to a phase transformation where a single liquid phase cools and transforms completely into two different solid phases?
Eutectic reaction
what is the material application of low carbon steel and percentage range does it fall into to justify it being low carbon steel?
Low carbon steel (often called mild steel) contains between 0.05% and 0.25% carbon. It is widely used because it is affordable, easy to weld, and very ductile (flexible without breaking).
Describe the function of a NAND gate and produce a logic table to support your response.
A NAND gate output is '0' only when both inputs are '1'.
A class-1 lever has an effort arm of 2.0 m and a load arm of 0.5 m. If a load of 200 N is applied at the load arm, what is the ideal mechanical advantage (MA) and the minimum effort force required to lift the load under ideal conditions?
MA = 4.0, effort = 50N
A box slides down an inclined ramp, at 25 degrees to the horizontal, at a constant velocity. The box experiences a normal force of 60 N. Its coefficient of kinetic friction is 0.47. Determine the mass of the parcel.
6.76kg
If a eutectoid steel is held at 650°C for only 5 seconds before a severe water quench, the remaining untransformed austenite will not finish growing into pearlite, but will instead instantly form this microstructure
What is Martensite?
Names 3 Properties and 1 real-world application of Polycarbonate
Properties [any 3 of] Extremely high impact resistance, Transparent, Heat resistant, Tough, Chemical resistant, Dimensionally stable.
Suggested Examples: automotive headlamp lenses, motorcycle windscreens and face shields, safety glasses, machinery guards, security windows, skylights, and streetlamp covers.
A washing machine is to turn on when the power switch is on, the door is closed and the water level is full. What logic gates are required to satisfy this context?
2 AND gates
A 22 kg object is placed a plane with a length of 13 metres and a height of 4 metres located on the moon (g=1.625 m/s^2). What is the coefficient of friction?
0.3076
A box is sitting on an incline plane with its end hanging over a 2m drop, with a resisting frictionary force of 30N and a coefficient of friction of 0.15. The incline sits at 20 degrees. Starting at rest, the box accelerates for 3 seconds before reaching a terminal velocity at the bottom of the ramp. Calculate the time it takes for the box to reach the floor after leaving the end of the incline.
2.32 seconds*
High carbon steel Is hypereutectoid which containing pearlite and proeutectoid cementite along grain boundaries. This results in high hardness and wear resistance but lower ductility and impact toughness. It is usually used in cutting tools and wipe ropes.
What carbon % steel would be most suitable for use in reinforced concrete? Justify with reference to a relevant mechanical property.
0.05% - 0.3% (Low carbon steel)
Properties [any one of] Soft/ductile, Machinable, Weldable, Good Toughness
An automated industrial conveyor system transports metal products to a robotic cutting station. The system contains sensors that ensure the cutting tool operates only when specific safety and operating conditions are satisfied. The cutting operation is permitted only when the conveyor is running and the metal product is detected, and at least one of the following conditions is satisfied: the protective cover is securely closed or the emergency stop button is not activated. However, the cutting operation must be prevented whenever the cutting tool is detected as incorrectly positioned.
Develop a logic gate circuit that produces an output of 1 when the cutting operation is permitted and an output of 0 when it is not permitted.
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