Question

A car travelling at 20 km/h speeds upto 60km/h in 6 seconds. What is its accelaration?​

Answer 1

$\huge\star\underline\mathtt\purple{Answer}$

$\sf{\bold{\green{\underline{\underline{Given :— }}}}}$

$\rm{ U = 20km/h}$

$\rm{ V = 60km/h}$

$\rm{ T = 6sec/h}$

$\small\red{\sf { Additional / Information:— }}$

⇢ U = Initial speed

⇢ V = Final speed

⇢ A = Acceleration

⇢ T = Time

$\sf{\bold{\pink{\underline{\underline{ Find :— }}}}}$

$\rm{ Acceleration = ?? }$

$\sf{\bold{\blue{\underline{\underline{Solution :— }}}}}$

In first we will change speed km/h to m/s !

$\rm{ 1km = 1000m and 1h = 3600 sec}$

⟾ $\sf{\bold{\blue{\boxed{1km/h = 1000 \ 3600}}}}$ m/s

Answer 2

$\sf{ \orange{\bigstar Given \longrightarrow }}$

$\rm{Initial \ speed = 20km/h}$$\rm{Final \ speed= 60km/h}$$\rm{Time = 6 sec}$

 

$\sf{ \red{\bigstar Find \longrightarrow }}$

$\rm{Acceleration-?}$

   

$\sf{ \blue{\bigstar Formula \ used \longrightarrow }}$

$\boxed{ \bf{a= \dfrac{v-u}{t} }}$

where,$\sf{a= acceleration}$

$\sf{v=final \ speed }$

$\sf{u = initial \ speed}$

$\sf{t= time}$

   

$\sf{ \green{\bigstar SoLution \longrightarrow }}$

First we will change speed km/h to m/s

we know,$\sf{1 km = 1000m \ and \ 1h = 3600 sec. }$

$\sf{\implies 1km/h =\dfrac{1000}{3600}m/s = \dfrac{5}{18}m/s }$

so Initial velocity [u] =>$\sf { \implies 20km/h = \dfrac{5}{18} \times 20 m/s = 5.55m/s}$

and Final velocity [v]$\sf{\implies 60km/h = 60 \times \dfrac{5}{18} m/s = 16.6m/s}$

 

According to Newton's 1st equation of motion,v = u + at

$\sf {\implies a= \dfrac{v-u}{t} }$

put the values in the formula we get,

$\sf{\implies a= \dfrac{16.66- 5.55}{6}}$

$\sf{\implies a= \dfrac{11.11}{6}}$

$\implies \boxed{\bf{ a= 1.85m/s^2 }}$

Therefore, Acceleration of the Car is 1.85m/s².

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