Question

A body of mass 250g is release from the top of a building. if the body hits the ground with a velocity of 4m/s, calculate th height of the building [g=10m/s²]​

Answer 1

$\purple{\maltese}\large\underline{\underline{\sf\:\: Given :}}$

» Mass ( m ) of the body = 250 g

» final velocity of the body = 4 m/s

$\\\purple{\maltese}\large\underline{\underline{\sf\:\: To \: \: Find :}}$

» The height of the Building= ??

$\\\purple{\maltese}\large\underline{\underline{\sf\:\: Solution :}}$

★ Height of the building by the principal of conservation;

$\\\\\begin{gathered}\purple{\maltese}\large\underline{\underline{\sf\:\: using \: formula :}} \\ \\\end{gathered}$

$\bigstar \: \underline{ \boxed{\sf { \pink{ \: \frac{1}{2} \: \: mv { }^{2} = \: mgh \: }}}}$

$\\ \: \: \underline{\textsf {Putting values \: in \: the \: \: given \: formula :}}$

$\\ \sf \implies \: \frac{1}{2} \: \: mv { }^{2} = \: mgh \:$

$\\ \sf \implies \: \frac{v {}^{2} }{2} \: \: = \: gh \:$

$\\ \sf \implies \: h \: = \frac{v {}^{2} }{2g} \: \: \:$

$\\ \sf \implies \: h \: = \frac{16 }{20} \: \: \:$

$\\ \sf \implies \: h \: = 0.8 \: \: \: m$

$\\ \sf \implies \: h \: = 80 \: \: \: cm$

henceforth , The height of the Building is 0.8 m or 80 cm ..!!!