Question

. A car takes 40 minutes to cover 40 km. Calculate the speed in (i.) km/h (ii.) m/s

Answer 1

Given :-

A Car Takes 40 minutes to cover 40 km .

To Find :-

The speed ( i ) In km/h ( ii ) In m/s

Solution :-

We knows that ;

$\quad \qquad { \bigstar { \underline { \boxed { \tt { Speed ( S ) = \dfrac{Distance \: ( D) }{ Time \: ( T ) } } } } } { \bigstar } }$

So , we are going to use this formulae ;

( i )

Here ,

• Distance = D = 40 km
• Time = T = 40 min

As here. ,Time is in minute but we have to find answer in km/h . So , We are going to convert minutes into hours .

$\quad \qquad { \tt { 1 min = \dfrac{1}{60} \: hour } }$

$\quad \qquad { \tt { \therefore 40 min = \dfrac{40}{60} \: hour } }$

Now , using the Formula we have ;

$\quad \qquad { \tt { Speed = D ÷ T } }$

$\quad \qquad { \tt { : \longmapsto S = 40 ÷ \dfrac{40}{60} } }$

$\quad \qquad { \tt { : \longmapsto S = 40 × \dfrac{60}{40} } }$

$\quad \qquad { \tt { S = 60 \: \: km/h } }$

( ii )

Here ;

• S = ?
• D = 40 km = 40 × 1000 = 40000 m
• T = 40 min = 40 × 60 sec

Now ,

$\quad \qquad { \tt { S = D ÷ T } }$

$\quad \qquad { \tt { : \longmapsto S = 40000 ÷ ( 40 × 60 ) } }$

$\quad \qquad { \tt { : \longmapsto S = \dfrac{40000}{40 × 60 } } }$

$\quad \qquad { \tt { : \longmapsto S = \dfrac{1000}{60 } } }$

$\quad \qquad { \tt { : \longmapsto S = \dfrac{100}{6} } }$

$\quad \qquad { \tt { : \longmapsto S = \dfrac{50}{3} \: \: m/s} }$

Henceforth , Done :)