Solve problems involving speed

Speed

9.1

Speed

	Definition

	The rate at which something moves or operates.

Speed as a rate:

	Definition

	It is the rate of change of distance with time.

Formula

\(\text{Speed} = \dfrac{\text{Distance}}{\text{Time}} \)

Uniform and non-uniform speed:

Uniform Speed	Non-uniform Speed
Covers at equal distance in equal interval of time It implies the movement of an object along a straight line with steady speed Similar to the actual speed of the object. The distance-time graph shows a straight line	Covers at unequal distance in equal interval of time It implies the movement of an object along a straight line with variable speed Different from the actual speed of the object The distance-time graph shows a curved line

Average speed:

Formula

\(\text{Average speed} = \dfrac{\text{Total distance}}{\text{Total time}}\)

	Example

	A truck travels \(132\text{ km}\) in \(22\text{ hours}\). What is the speed of the truck?

	Answer: We’re looking for speed, the distance should be divided by time. \(\begin{aligned} \space \text{Speed}&= \dfrac{\text{Distance}}{\text{Time}} \\\\& = \dfrac{132 \space\text{km}}{22 \space \text{h}} \\\\&= 6 \space \text{km/h}. \end{aligned}\)

9.1

Speed

	Definition

	The rate at which something moves or operates.

Speed as a rate:

	Definition

	It is the rate of change of distance with time.

Formula

\(\text{Speed} = \dfrac{\text{Distance}}{\text{Time}} \)

Uniform and non-uniform speed:

Uniform Speed	Non-uniform Speed
Covers at equal distance in equal interval of time It implies the movement of an object along a straight line with steady speed Similar to the actual speed of the object. The distance-time graph shows a straight line	Covers at unequal distance in equal interval of time It implies the movement of an object along a straight line with variable speed Different from the actual speed of the object The distance-time graph shows a curved line

Average speed:

Formula

\(\text{Average speed} = \dfrac{\text{Total distance}}{\text{Total time}}\)

	Example

	A truck travels \(132\text{ km}\) in \(22\text{ hours}\). What is the speed of the truck?

	Answer: We’re looking for speed, the distance should be divided by time. \(\begin{aligned} \space \text{Speed}&= \dfrac{\text{Distance}}{\text{Time}} \\\\& = \dfrac{132 \space\text{km}}{22 \space \text{h}} \\\\&= 6 \space \text{km/h}. \end{aligned}\)