Mechanics - Scalars and Vectors

Question 1

Scalar quantities

Answer 1

have magnitude not direction (e.g. distance, speed, time, mass, energy, temperature, power).

Question 2

Vector quantities

Answer 2

have magnitude and direction (e.g. displacement, velocity, acceleration, force, moment, momentum, current).

Question 3

Distance/Displacement

Answer 3

metres [m] (/+ direction)

Question 4

Speed/Velocity

Answer 4

metres per second [m s-1] (/+ direction)

Question 5

Scalar Addition

Answer 5

Magnitude = Σ values.

Question 6

Vector Addition:

Answer 6

Magnitude = Σ values (parallel) or Pythagoras’ Theorem (perpendicular). Direction = Sign (parallel) or Trigonometry (perpendicular).

Question 7

Components

Answer 7

Through the angle = cosine. Away from the angle = sine. Perpendicular vectors are mutually independent.