Question

A car travels along a straight road to East for 120 metres in 5 seconds. Then go to the west for 60 metres in 1 second. Determine average speed and average velocity.

Answer 1

Given:

A car travels along a straight road to East for 120 metres in 5 seconds. Then go to the west for 60 metres in 1 second.

To find:

Average speed and Average Velocity.

Calculation:

$avg. \: s = \dfrac{total \: distance}{total \: time}$

$= > avg. \: s = \dfrac{120 + 60}{5 + 1}$

$= > avg. \: s = \dfrac{180}{6}$

$\boxed{ = > avg. \: s = 30 \: m {s}^{ - 1} }$

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$avg. \: v = \dfrac{total \: displacement}{total \: time}$

$= > avg. \: v =\dfrac{120-60}{5+1}$

$= > avg. \: v =\dfrac{60}{5+1}$

$= > avg. \: v =\dfrac{60}{6}$

$\boxed{= > avg. \: v =10 m{s}^{-1}}$

• Average speed is denoted by the total distance divided by the total time.

• Average velocity is denoted by the total displacement divided by the total time.

Answer 2

Diagram:-

$\setlength{\unitlength}{1cm}</p><p>\begin{picture}(6,6)</p><p></p><p>\put(3, 3){\vector(1, 0){2}}</p><p>\put(5, 2.5){\vector(-1, 0){1}}</p><p>\put(3,3){\circle*{0.07}}</p><p>\put(3.5,3.1){\footnotesize{\sf{120m}}}</p><p>\put(4.2,2.28){\footnotesize{\sf{60m}}}</p><p></p><p>\end{picture}$

Average Speed:-

Average Speed = (Total distance)/(Total time)

→ Average Speed = (120m + 60m)/(5s + 1s)

→ Average Speed = 180/6 m/s

→ Average Speed = 30 m/s

Average Velocity:-

Average Velocity = (Total displacement)/(Total time)

Total Displacement = 60m

→ Average Velocity = (60m)/(5s + 1s)

→ Average Velocity = (60m)/(6s)

→ Average Velocity = 10m/s

Ans. Average Speed = 30 m/s, Average Velocity = 10 m/s