Question

Aniket is skating at 25 m/s. He
experiences retardation of 5
m/s2. How many seconds will
it take to stop him???
Just right Number without unit.​

Answer 1

Given:-

• Initial velocity , u = 25m/s

• Retardation ,a = 5m/s²

• Final velocity ,v = 0m/s

To Find:-

• Time taken ,t

Solution:-

As we know that retardation is negative acceleration.

By using 1st equation of motion

• v = u+at

Substitute the value we get

→ 0 = 25 + (-5)×t

→ -25 = -5 ×t

→ t = -25/-5

→ t = 25/5

→ t = 5 s

Therefore, the time taken to stop the skate is 5 Second.

Answer 2

$\tt \huge{ \bold{ \boxed{ \underline{ \orange{Given : }}}}} \\ \\ \\ </p><p></p><p></p><p> \bf \large \bull \: initial \: velocity \: (u) = 25 \: m/s \\ \\ </p><p> \bf \large \bull \: Final \: velocity \: (v) = 0 \: m/s \\ \\ \bf \large \bull</p><p>retardation = - \: 5 \: m {s}^{ - 2} \\ \\ \\ </p><p></p><p></p><p> \tt \huge{ \bold{ \boxed{ \underline{ \purple{ To \: find : }}}}} \\ \\ </p><p></p><p> \sf \large \bull{ \underline{time \: taken \: (t) = \: ?}} \\ \\ \\ </p><p></p><p> \bf \huge { \boxed{ \underline{ \bold{ \pink{Solution }}}}} \\ \\ \\ </p><p></p><p> \sf \implies \large \: Through \: first \: equation \: of \: motion \\ \\ </p><p></p><p></p><p> \bf \bull \large{ \boxed{ \boxed{ \underline { \bold{v = u + at }}}}} \\ \\ </p><p></p><p></p><p> \sf \large \iff \: placing \: the \: values \\ \\ </p><p></p><p> \sf \large \implies \: 0 \: = \: 25 \: + \: (-5) \: t \\ \\ </p><p></p><p> \sf \large \implies \: 0 \: = \: 25 \: - \: 5t \\ \\ </p><p></p><p> \sf \large \implies \: 25 \: = \: 5t \\ \\ \sf \large \implies \: t \: = \cancel \frac{25}{5} \\ \\ \bf \implies \large { \boxed{ \: t = 5 \: s}} \\ \\ \\ </p><p></p><p></p><p> \bf \bull \large \therefore \: the \: time \: taken \: is \: 5 \: seconds$