Question

A girl walks a distance of 4 km in 2 hrs . Find her speed in meter per second (m/s).

Answer 1

Provided that:

• Distance = 4 km
• Time = 2 hrs

To calculate:

• Speed in mps

Solution:

• Speed = 0.55 mps

Using concepts:

• Formula to calculate speed
• Formula to convert kmph-mps

Using formulas:

• Speed is given by the mentioned formula:

• ${\small{\underline{\boxed{\pmb{\sf{v \: = \dfrac{s}{t}}}}}}}$

• Formula to convert kmph-mps:

• ${\small{\underline{\boxed{\pmb{\sf{1 \: kmph \: = \dfrac{5}{18} \: mps}}}}}}$

Where, v denotes velocity, s denotes distance and t denotes time.

Required solution:

~ Let us find out the distance travelled by using suitable formula in kmph!

$:\implies \sf Velocity \: = \dfrac{Distance}{Time} \\ \\ :\implies \sf v \: = \dfrac{s}{t} \\ \\ :\implies \sf v \: = \dfrac{4}{2} \\ \\ :\implies \sf v \: = 2 \: kmph \\ \\ :\implies \sf Velocity \: = 2 \: kmph$

~ Now let us convert kmph-mps!

$:\implies \sf 1 \: kmph \: = \dfrac{5}{18} \: mps \\ \\ :\implies \sf 2 \: kmph \: = 2 \times \dfrac{5}{18} \: mps \\ \\ :\implies \sf 2 \: kmph \: = \dfrac{10}{18} \: mps \\ \\ :\implies \sf 2 \: kmph \: = \dfrac{5}{9} \: mps \\ \\ :\implies \sf 2 \: kmph \: = 0.55 \: mps$

Henceforth, speed = 0.55 mps

Answer 2

• Distance travelled=4km
• Time=2h

We know

$\boxed{\sf Speed=\dfrac{Distance}{Time}}$

$\\ \sf\longmapsto Speed=\dfrac{4}{2}$

$\\ \sf\longmapsto Sped=2km/h$

• Converting to m/s

$\\ \sf\longmapsto 2\times \dfrac{5}{18}$

$\\ \sf\longmapsto \dfrac{5}{9}$

$\\ \sf\longmapsto 0.5m/s$