$ -80=-\mathrm{v}_1 \mathrm{t}-\frac{1}{2} \times 10 \mathrm{t}^2 $
$ -80=-2 \mathrm{v}_1-\frac{1}{2} \times 10 \times 2^2 $
$ -80=-2 \mathrm{v}_1-20 $
$ -60=-2 \mathrm{v}_1 $
$ \mathrm{v}_1=30 \mathrm{~m} / \mathrm{s}$
From $\mathrm{O}$ to $\mathrm{A}$
$ \mathrm{v}^2=\mathrm{u}^2+2 \mathrm{gS} $
$ 30^2=0+2 \times(-10)(-\mathrm{S}) $
$ 900=20 \mathrm{~S} $
$ \mathrm{~S}=45 \mathrm{~m}$
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
| Column $-I$ $R/H_{max}$ |
Column $-II$ Angle of projection $\theta $ |
| $A.$ $1$ | $1.$ ${60^o}$ |
| $B.$ $4$ | $2.$ ${30^o}$ |
| $C.$ $4\sqrt 3$ | $3.$ ${45^o}$ |
| $D.$ $\frac {4}{\sqrt 3}$ | $4.$ $tan^{-1}\,4\,=\,{76^o}$ |