Unit 1 - Motion

Question 1

Name 3 base units

Answer 1

Metre (m)

Second (s)

Kilogram (kg)

Other incl - amp, kelvin, mole, cd (luminous intensity)

Question 2

Name a supplementary unit related to angle

Answer 2

Radians (rad)

1 rad = 57.296 degrees

Question 3

What is the difference between a scalar and vector?

Answer 3

Scalar concerns magnitude (e.g. distance, speed)

Vector has a magnitude with direction (e.g. displacement, velocity)

Question 4

What does the Cartesian coordinate system refer to?

Answer 4

x, y, z axes

as they are all at right angles to each other and independent, they are said to be orthogonal

Question 5

What do polar coordinates describe?

Answer 5

The angle (or 2 if for 3D) and length of a line

Question 6

How many degrees of freedom may an object have?

Answer 6

6:

• 3 independent translations
• 3 independent rotations

Question 7

For linear motion, what are the equations for:

• velocity?
• acceleration?

Answer 7

v = d/t

a= Δv/t

Question 8

What are the SUVAT equations?

Answer 8

v = u + at

s = 1/2(u + v)t

v^2 = u^2 + 2as

s = ut + 1/2at^2

Question 9

What do the following symbols mean in relation to rotary motion:
θ
ω
α

Answer 9

θ = angular displacement (rad)

ω = angular velocity (rad/s)

α = angular acceleration (rad/s^2)

These can be substituted into suvat equations