wave motion

Question 1

Mechanical wave

Answer 1

Produced by particle oscillation. Requires a propagation medium (solid, gas, liquid).

Question 2

Longitudinal wave

Answer 2

Sound

Question 3

Transversal wave

Answer 3

this formed by string attached to a stringed instrument

Question 4

Amplitude(a)

Answer 4

Maximum displacement from mean position

Energy = a^2

Question 5

Wavelength (l)

Answer 5

distance between two peaks (or two troughs) or two compressions (or rarefactions)

Question 6

Electromagnetic waves

Answer 6

self propagating waves with electrical and magnetic components. They travel at speed of light (3 × 10^8 m s^-1)

Question 7

speed of light

Answer 7

3 × 10^8 m s^-1

Question 8

inside a closed system, ______ & _____ occur but the ______ is the same.

Answer 8

physical and biochemical changes occur

mass is the same

Question 9

Total balance

Answer 9

Total mass crossing the boundaries

Question 10

Specific component balance

Answer 10

Mass balance is done for one component within the system

Question 11

Isolated system

Answer 11

the sum of all forms of energy remains constant, there may be inter-conversion between the many different forms (mechanical, electrical, magnetic, thermal, chemical and nuclear).

Question 12

Principle of energy conservation

Answer 12

Energy cannot be created or destroyed, although it can be altered from one form into another

Question 13

Potential energy (Eg)

Answer 13

. Associated with position in gravitational field:

Eg = mgh

Question 14

Kinetic energy

Answer 14

energy associated with movement

K= (1/2) / mv^2

mass (m) ; speed (v)

Question 15

Pressure energy (Ep)

Answer 15

Associate with the pressure in a fluid

Question 16

Mechanical energy

Answer 16

Potential energy + Kinetic energy + Pressure energy

Eg + K + Ep

Question 17

Bernoulli’s Equation

Answer 17

p + (1/2) pV^2 + pgh = constant

( pressure + 1/2 density. velocity ^2 + density. gravity. height of head)

• points 1 and 2 lie on a streamline,
• the fluid has constant density,
• the flow is steady, and
• there is no friction

[v(1)^2 /2] + gh(1) + p(1)/ density = [v(2)^2 /2] + gh(2) + p(2)/ density