PHYSICS

Think back to GCSE

1.Write down the definition of velocitySpeed in a given direction

2.Write down the calculation for velocityBut that is how you calculate speed,

which you just said is different to velocity

Monday 10 April 2023

1.1.2 Scalars and Vectors

Learning Objectives:

•Understand the difference between scalars and vectors.•Add and subtract vectors.•Work out the x and y components of a vector.

Distance (x)Displacement (s)

Velocity (v) = Displacement (s)Time (t)

Speed (v) = Distance (x) Time (t)

Scalar Vector

Magnitude

Direction

Magnitude

Vectors• Some quantities need to have a direction to

be meaningful.• Force for instance can be big or small but we

need to know the direction it acts if it is to be useful.

• Vectors are quantities that have BOTH a Magnitude and a Direction

• We can represent them with ARROWS

10 N Right 10 N Left or -10N

• Velocity

• Acceleration

• Momentum

• Force

• Displacement

• Electric field strength

• Time

• Distance

• Speed

• Temperature

• Mass

• Power

• Energy

Vectors Scalars

Vector Addition

• Is not like ordinary arithmetic • You have to take account of the direction• Two ways to do it

– Scale drawing– Trigonometry

H O

A

Fy

Fx

F

= Fcos

= Fsin