Question

A ball is projected on the strain from the horizontal with velocity u. The maximum number of strains that can be completed crossed is

• A. $\frac{2{{u}^{2}}h}{g{{b}^{2}}}$
• B. $\frac{{{u}^{2}}h}{g{{b}^{2}}}$
• C. $\frac{2{{u}^{2}}b}{gh}$
• D. $\frac{{{u}^{2}}b}{gh}$

Answer 1

Answer: (A)

$\frac{2{{u}^{2}}h}{g{{b}^{2}}}$

Answer 2

Coordinate of point $(nb,nh)$ and $\theta =0$ From equation of projectile, $y=x\tan \theta -\frac{g{{x}^{2}}}{2{{u}^{2}}{{\cos }^{2}}\theta }$ $nh=nb\tan 0{}^\circ -\frac{g{{n}^{2}}{{b}^{2}}}{2{{u}^{2}}{{\cos }^{2}}0{}^\circ }$ $nh=\frac{g{{n}^{2}}{{b}^{2}}}{2{{u}^{2}}}$ $n=\frac{2h{{u}^{2}}}{g{{b}^{2}}}$