Topic 1- Motion, Forces and Conservation Of Energy

Question 1

Vectors

Answer 1

• Have magnitude
• Have directions
• Examples are displacement, velocity and momentum

Question 2

Scalars

Answer 2

• Only involve magnitude
• Don’t have any direction
• Examples of scalars are speed, distance and temperature

Question 3

Distance

Answer 3

• How far an object has moved
• Does not invlove direction
• Distance = Speed x time

Question 4

Displacement

Answer 4

• Diplacement is a vector quantity
• It measures the distance an direction from a starting point.
• e.g the plane flew five metres north
• The point could also be a bearing e.g 35 degrees
• ## If you walk 10m north then 10m south, your overall displacement is 0m, but the distance travelled is 20m

Question 5

Speed

Answer 5

• How fast you are going
• Measured in mph or m/s
• Distance = Speed x Time

Question 6

Velocity

Answer 6

• Speed in a given direction
• 30 mph north or 35 degress
• Objects can travel at a constant soeed but at a changing velocity, if they change direction
• Objects rarely travel at a constant thougj

Question 7

Average velocity

Answer 7

Walking 1.4m/s or 5kmh, Running 3 m/s or 11kmh, Cycling 5.5m/s or 20kmh, Cars 13m/s or 47 kmh, Planes 250 m/s or 900 kmh, Cars on a Motorway 31 m/s or 112kmh, Trains up to 55 m/s or 200kmh, Wind speed 5-20 m/s, Speed of Sound in air 340 m/s and Ferries 15 m/s to 54 kmh

Question 8

Acceleration

Answer 8

• How fast you are speeding up, measured in m/s squared
• Change in velocity over a certain time
  a = (v-u)
  ——
  t
• acceleration = a, v is final velocity, u is initial and t is time
• Deceleration is negative acceleration

Question 9

Unifom Acceleration

Answer 9

• Uniform acceleration is constant acceleration
• This is the equation for uniform acceleration
  V squared - u squared
  =
  2ax