Question

racing car at rest accelerates uniformly to a velocity of 144 km per hour in 20 seconds find the value of acceleration of the car​

Answer 1

• Step-by-step explanation:

40m/sec/20 sec =2m/sec2(square)

Answer 2

$\boxed{ \underline{ \underline{\bigstar\tt\purple{ \: Solution:-}}}}$

$\: \: \: \: \: \: \: \: \: \: \: \: \:$

$\footnotesize\tt \purple{Given:-}$

$\: \: \: \: \: \: \: \: \: \: \: \:$

$\footnotesize\tt{u = 0 \: (Because \: car \: is \: at \: rest)}$

$\footnotesize\tt{v = 144 \: km \: per \: hour}$

$\footnotesize\tt{t=20 \: sec}$

$\: \: \: \: \: \: \: \: \: \: \: \: \:$

$\footnotesize\tt \purple{Now, convert \: v \: in \: \: m \: per \: sec}$

$\: \: \: \: \: \: \: \: \: \: \: \: \:$

$\footnotesize\tt{v = \cancel{144} \: \times \: } \tt{ \frac{5}{ \cancel{18}} \: \: m \: per \: sec }$

$\footnotesize\tt{v = 8 \: \times 5 \: m \: per \: sec }$

$\footnotesize\tt{v = 40\: m \: per \: sec }$

$\: \: \: \: \: \: \: \: \: \: \: \: \:$

$\footnotesize\tt \purple{Now, find \: Acceleration \: (a)}$

$\: \: \: \: \: \: \: \: \: \: \: \: \:$

$\footnotesize\tt{v = u + at}$

$\footnotesize\tt{40= 0 + a \times 20}$

$\footnotesize\tt{40= 0 + 20a}$

$\footnotesize\tt{40 - 0= 20a}$

$\footnotesize\tt{40 = 20a}$

$\tt{ \frac{40}{20}} \: \footnotesize \tt{= a}$

$\tt{ \cancel\frac{40}{20}} \: \footnotesize \tt{= a}$

$\boxed{ \underline{ \underline{ \footnotesize \tt \purple{a = 2 \: m {s}^{ </strong><strong>2</strong><strong>}</strong><strong> }}}}$

$\: \: \: \: \: \: \: \: \: \: \: \:$

$\</strong><strong>f</strong><strong>o</strong><strong>o</strong><strong>t</strong><strong>n</strong><strong>o</strong><strong>t</strong><strong>e</strong><strong>s</strong><strong>i</strong><strong>z</strong><strong>e</strong><strong>\</strong><strong>t</strong><strong>t</strong><strong>{</strong><strong>Extra:</strong><strong>-</strong><strong>}</strong><strong>$

$\: \: \: \: \: \: \: \: \: \: \: \:$

$\footnotesize\tt \purple{Now, find \:Distance \: (s)}$

$\: \: \: \: \: \: \: \: \: \: \: \:$

$\footnotesize\tt{s= ut + \frac{1}{2} a {t}^{2} }$

$\footnotesize\tt{s= 0 \times 20+ \frac{1}{2} \times 2 \times {20}^{2} }$

$\footnotesize\tt{s=0 \: + \: } \tt{\frac{1}{ \cancel2} \: } \footnotesize\tt{ \times \: \cancel 2 \times {20}^{2} }$

$\footnotesize\tt{s=0 \: + \: {20}^{2} }$

$\footnotesize\tt{s=0 \: + \: 400 }$

$\boxed{ \underline{ \underline{\footnotesize\tt \purple{s= 400 \: m}}}}$