Question

A body accelerates uniformly at rest and require speed at 72km/h in 20s find the acceleration of body in m/s square
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Answer 1

Provided that:

• Initial velocity = 0 mps
• Final velocity = 72 kmph
• Time = 20 seconds

To calculate:

• Acceleration

Solution:

• Acceleration = 1 m/s sq.

Using concepts:

• Formula to convert kmph-mps
• Acceleration formula

Using formulas:

• Formula to convert kmph-mps:

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

• Acceleration formula:

• ${\small{\underline{\boxed{\pmb{\sf{a \: = \dfrac{v-u}{t}}}}}}}$

Required solution:

~ Firstly let us convert kmph-mps!

$:\implies \sf 1 \: kmph \: = \dfrac{5}{18} \: mps \\ \\ :\implies \sf 72 \: kmph \: = 72 \times \dfrac{5}{18} \: mps \\ \\ :\implies \sf 72 \: kmph \: = \cancel{72} \times \dfrac{5}{\cancel{{18}}} \: mps \: (Cancelling) \\ \\ :\implies \sf 72 \: kmph \: = 4 \times 5 \: mps \\ \\ :\implies \sf 72 \: kmph \: = 20 \: mps \\ \\ {\pmb{\sf{Henceforth, \: converted!}}}$

~ By using acceleration formula, let's find out the acceleration!

$:\implies \sf a \: = \dfrac{v-u}{t} \\ \\ :\implies \sf a \: = \dfrac{20-0}{20} \\ \\ :\implies \sf a \: = \dfrac{20}{20} \\ \\ :\implies \sf a \: = 1 \: mps^{-2} \\ \\ :\implies \sf Acceleration \: = 1 \: mps^{-2}$