Chapter 11.1 - Linear Motion

Question 1

Define centre of mass

Answer 1

the centres of mass is the balance point of an object. Another term is centre of gravity.

Question 1

Define position

Answer 1

• positions describes the location of an object at a certain point in time with respect to the origin.
  -Position is a vector quantity and therefore requires a direction.

Question 2

Define distance travelled

Answer 2

-Distance travelled describes the length of the path covered by an object over the entire journey.
-Distance travelled is a scalar quantity and is measured in meters(m).
-Position describes where an object is at a certain point in time. However, distance travelled is how far a body travels during a journey.

Question 3

Define displacement

Answer 3

-Displacement is the change in position of an object. Displacement takes into account only where the motion starts and finishes.
-Displacement –> s= final position - initial position.

Question 4

Total displacement

Answer 4

Sum of individual displacements.

Question 5

Define speed

Answer 5

-Speed is the rate at which the distance is travelled.
-A direction is not required when describing the speed of an object.

Question 6

Define Velocity

Answer 6

Velocity is the rate at which displacement changes, and so is vector quantities.
-The SI unit for speed and velocity is metres per second (ms^-1),but kilometres per hour (kmh^-1) is also commonly used.

Question 7

Formula for average speed

Answer 7

average speed (v)= Distance travelled/Time taken =

Question 8

Formula for velocity

Answer 8

average velocity (v)= displacement/time taken