Question

Ｃａｌｃｕｌａｔｅ ｔｈｅ ｗｏｒｋ ｄｏｎｅ ｒｅｑｕｉｒｅｄ ｔｏ ｓｔｏｐ ａ ｃａｒ ｏｆ ｍａｓｓ ５０ ｋｇ ｍｏｖｉｎｇ ｗｉｔｈａ ｖｅｌｏｃｉｔｙ ｏｆ ５４ ｋｍ／ｈ

Answer 1

$\begin{gathered} \bf{ \pmb{ \gray { \underline{GIVEN }}}} \\ \tt{ Mass \: of \: a \: body \: → \: 50kg }\\ \tt \: Velocity \: of \: body \: → \: 54km/hr \\ \\ \bf{ \pmb{ \gray{ \underline{ TO \: \: FIND }}}}\\ \tt \: \blue{Work \: done \: by \: body} \\ \\ \bf{ \pmb{ \gray{ \underline{SOLUTION}}}} \\ \small{ \sf \: According \: to \: Work \: Energy \: Theorem :−} \\ \\ \begin{gathered}\sf\red{ \boxed{ \bf Work \ Done = \Delta Energy_{Kinetic\ energy} } }\\\\\rm \small\: Work \ Done = \dfrac{1}{2}mv^2- \dfrac{1}{2}mu^2 \\\\\rm \small \: Work \ Done = \dfrac{1}{2}m ( v^2 - u^2 ) \\\\\rm \small Work \ Done = \dfrac{1}{2}\times 50kg [ (0m/s)^2 - (54km/hr)^2 ] \\\\\rm \small Work \ Done = 25kg \bigg\lgroup 0m^2/s^2 - \bigg(54 \times \dfrac{5}{18}m/s.\bigg)^2 \bigg\rgroup \\\\\rm \small \: Work \ Done = 25kg [ 0m^2/s^2 - (15m/s)^2 ] \\\\\rm \small \: Work \ Done = 25kg \times - 225 m^2/s^2 \\\\ \large \boxed{\blue{\mathbb {WORK \ DONE = -5625 \ JOULES .} }}\end{gathered} \end{gathered}$

Answer 2

Answer:

Mass of body= 50kg

Velocity of body= 54km/ h

Work done= Delta kinetic energy

Work done = 1/2 mv square - 1/2 mu square

Work done = 1/2m ( v square - u square

work done=1/2× 50kg ((0m/s square -(54km))

Work done = 25kg × -225m square

Work done = -5625 joules