Overview and introduction Flashcards
What is pressure?
The force that acts at right angles per unit of surface area of something in a fluid or gas
What is gauge pressure?
The difference b/n the measured pressure and atmospheric pressure
What is oscillation? Where is this found in the car?
To and from movement of a vibrating object or system. It’s found in suspensions. We use dampers or shock absorbers to prevent the springs from oscillating
What is energy? What is the measurement?
The ability to do work. It is work that is stored up. Measured in joules
What is power? What is it’s measurement?
The rate of doing work or converting energy. Measured in watts
What is the equation for power?
P=E/T
P=power
E=work done aka energy
T=Time
What is force? What is it’s measurement?
A vector quantity. Force must have size and direction. Measured in N (newtons)
What is torque?
Turning effect of force
What is density?
The measure of compactness of a substance. Measured in kg/m3 D=m/V D=density m= mass V= volume
What is relative density?
The ratio of density of one substance to another
What is heat? What is it’s measurement?
A form of energy that depends on the vibrating movement or kinetic energy of its molecules or atoms. Measured in Joules
How does heat flow?
It flows from a higher temperature to a lower temperature
What happens to an object when heat is applied?
It either increases in temperature or the material may expand
What happens when gases are confined?
It will increase in pressure
What is convection?
The transmission of heat through liquid or gas in currents. Like when the air in a car is warmed by a heater blower
What is radiation?
Heat transferred by infrared rays
What are gears?
Toothed wheels that transmit turning movement of one shaft to another
What determines the gear ratio?
The amount of teeth on the two gear wheels
What is the torque ratio?
The turning force on the output shaft compared w/ turning force on input shaft
What is the speed ratio?
The speed of the output shaft compared to speed of the input shaft
Give an example of gear ratio
Gear of ratio of 2:1 (20 input, 10 output). This means twice the speed output but half the torque input. Input usually has more torque whereas speed is multiplied in the outputs
What are hydraulics?
The use of liquid properties to transmit pressure and movement
Describe uses of hydraulics
Hydraulics uses pressurized liquid can increase mechanical efficiency. This can be found in vehicle braking and hydraulic jacks
What are the 2 liquid connected pistons in the cylinders of a basic hydraulic system?
The narrow bore and the large bore. Force applied to the narrow piston applies some pressure to the liquid and is then transmitted to the larger piston
Describe force multiplication b/n the larger and smaller piston
The larger piston has more force exerted on it. The force may be increased but the smaller piston has to move a great distance to move the larger piston by a small distance. Therefore, mechanical advantage is gained in force (increased force) but movement is lost (more movement needed)
What is corrosion and what are examples?
Corrosion is the eating away and destruction of metals and alloys. Examples include rusting of iron and steel through oxidation and creates iron oxide (rust)
What is the key to compression fitting?
The interference fit. The component ie. bearing, is slightly larger than the hole it’s trying to be fitted in
What is a gasket?
a pressure and fluid tight seal b/n two faces. In engine, it handles high pressures and temperatures. Gaskets make up for imperfect surfaces as it it’s a seal
What is a sealant?
Liquid rubber or instant gaskets that joins surfaces. It’s easier to apply, there’s little space taken up, and there’s reduced fretting from vibration (less likely to leak)
What is an oil seal?
A synthetic rubber seal that can tighten when pressure is applied. Excellent at preventing oil from entering combustion chamber
