UNIT-2: Forces And Moments

Question 1

Cartesian system of coordinates

Answer 1

A system that specifies each point uniquely via a group of real numbers

Question 2

Cylindrical system

Answer 2

A 3D coordinate system which describes a point using:
- a radius (r)
- azimuthal angle (θ)
- a height (z)

Form:
P(r, θ, z)

Question 3

Spherical system

Answer 3

A 3D coordinate system which describes a point using:
- a radius (ρ)
- azimuthal angle (φ)
- angle with positive x-axis (θ)

Form:
P(ρ, θ, φ)

Question 4

Moments

Answer 4

A measure of the tendency to cause a body to rotate about a specific point or axis

Question 5

Equilibrium law of moments

Answer 5

For an object to be in equilibrium, the sum of the clockwise and anticlockwise about a pivot point must be zero

Question 6

Couples

Answer 6

Rotational effect caused by 2 equal and opposite forces that are parallel and separated by a distance, resulting in a net moment, but no net force