CBSE-XI-Physics

03: Rest and Motion: Kinematics

with Solutions - page 2
Qstn# B-10 Prvs-QstnNext-Qstn
  • #10
    The range of a projectile fired at an angle of 15° is 50 m. If it is fired with the same speed at an angle of 45°, its range will be
    -(a) 25 m
    (b) 37 m
    (c) 50 m
    (d) 100 m
    digAnsr:   d
    Ans : (d) 100 m
    For the same u range, `` R\propto \,\mathrm{\,sin \,}\left(2\theta \right)``.
    So,
    `` \frac{{R}_{1}}{{R}_{2}}=\frac{\,\mathrm{\,sin \,}\left(2{\theta }_{1}\right)}{\,\mathrm{\,sin \,}\left(2{\theta }_{2}\right)}``
    `` \Rightarrow {R}_{2}=50\times \frac{\,\mathrm{\,sin \,}\left(90\right)}{\,\mathrm{\,sin \,}\left(30\right)}=100\,\mathrm{\,m \,}``