DLISC1 - week 11

Question 1

what are kinematics?

Answer 1

Is the branch of mechanics that describe the motion of objects, without considering the forces causing the motion
It deals with concepts such as position, velocity, acceleration and time and how these quantities are related to each other

Question 2

what are dynamics?

Answer 2

Dynamics is the branch of mechanics that deals with the causes of motion, specifically the forces that cause objects to move
It involves studying how forces affect the motions of objects, how they interact with each other, and how they cause objects to accelerate

Question 3

what is energy, kinetic energy and potential energy

Answer 3

energy: the capacity or power to do work by the application of force

kinetic energy: is the energy possessed by an object due to its motion

potential energy: the energy stored in an object due to its position

Question 4

examples of potential energy

Answer 4

Apples on a tree
Water stored in a dam
Compressed spring
Stretched rubber band
Crossbow

Question 5

examples of kinetic energy

Answer 5

Rotating fan
Car in motion
Man surfing
Boy playing football
High speed train

Question 6

components of motion

Answer 6

Position (where you are or were)
Speed/velocity – how position changes over time (in metres/second, m/s)
Acceleration – how your velocity changes over time (in meters/second squared)
Time – how long you were moving (in seconds, s)
Distance/displacement) – how far you have moved (in meters, m)

Question 7

what is the fluid flow?

Answer 7

A fluid is a substance in the liquid or gas phase
The fluid flow is the movement of a fluid in a certain direction
1. The layers
2. The streamline
3. The density

Question 8

two types of fluid flow

Answer 8

steady (laminar) flow
turbulent flow

Question 9

internal vs external flow

Answer 9

External: the flow of an unbounded fluid over a surface such as a plate, wire or a pipe.
Internal: the flow in a pipe or duct if the fluid is completely bounded by solid surfaces.

Question 10

what is bernoulli’s principle

Answer 10

Conservation law of energy
The relation between velocity and pressure

Question 11

what is bernoulli’s equation

Answer 11

Energy per unit volume before = energy per unit volume after

Question 12

what happens when the velocity of a flow inside the tube increases?

Answer 12

The pressure inside the tube decreases gradually, by increasing the velocity and vice versa.
Increase in the speed of the fluid occurs simultaneously with a decrease in the fluids potential energy.