Chapter 2: Kinematics

Question 1

Define distance

Answer 1

Distance, d, is the total length of the path travelled by an object. Distance is a scalar qty and its SI unit is metre (m).

Question 2

Define displacement

Answer 2

Displacement of an object is its distance from a fixed point in a specific direction. It is a vector qty and its SI unit is metre (m).

Question 3

Define speed

Answer 3

The speed of a body is defined as the rate of change of the distance travelled. It is a scalar qty and it’s SI unit is metre per second (ms^-1)

Question 4

Define average speed

Answer 4

Average speed of a body is defined as the total distance travelled over total time taken

<speed> = total distance travelled / total time taken
</speed>

Question 5

Define velocity

Answer 5

The velocity of a body is defined as the rate of change of its displacement. It is a vector qty ad its SI unit is metre per second (ms^-1)
v = ds/dt

Question 6

Define average velocity

Answer 6

Average velocity of an object is defined as change in displacement over total time taken.

<v> = Δs/Δt = (sf - si)/Δt
</v>

Question 7

Define acceleration

Answer 7

The acceleration of a body is defined as the rate of change of its velocity. It is a vector qty and its SI unit is metre per second squared (ms^-2)
a = dv/dt
Acceleration can only occur when the velocity is changing in magnitude and/or direction.

Question 8

Define average acceleration

Answer 8

<a> = Δv/Δt = (vf - vi)/Δt</a>

Question 9

State the equations for kinematics

Answer 9

v = u + at
s = ut + (1/2)at^2
V^2 = u^2 + 2as
Where u = initial velocity
v = final velocity
s = Δdisplacement
a = acceleration of body btwn initial and final positions
t = time taken for body to move from initial position to final position