The Cartesian equation of trajectory is (where u = Velocity of projection, $$\alpha $$ = Angle of projection and x, y = Co-ordinates of any point on the trajectory after t seconds.)
A. $${\text{y}} = \frac{{{\text{g}}{{\text{x}}^2}}}{{2{{\text{u}}^2}{{\cos }^2}\alpha }} + {\text{x}}\tan \alpha $$
B. $${\text{y}} = \frac{{{\text{g}}{{\text{x}}^2}}}{{2{{\text{u}}^2}{{\cos }^2}\alpha }} - {\text{x}}\tan \alpha $$
C. $${\text{y}} = {\text{x}}\tan \alpha - \frac{{{\text{g}}{{\text{x}}^2}}}{{2{{\text{u}}^2}{{\cos }^2}\alpha }}$$
D. $${\text{y}} = {\text{x}}\tan \alpha + \frac{{{\text{g}}{{\text{x}}^2}}}{{2{{\text{u}}^2}{{\cos }^2}\alpha }}$$
Answer: Option C
The resultant of two equal forces P making an angle $$\theta ,$$ is given by
A. $$2{\text{P}}\sin \frac{\theta }{2}$$
B. $$2{\text{P}}\cos \frac{\theta }{2}$$
C. $$2{\text{P}}\tan \frac{\theta }{2}$$
D. $$2{\text{P}}\cot \frac{\theta }{2}$$
A. Equal to
B. Less than
C. Greater than
D. None of these
If a number of forces are acting at a point, their resultant is given by
A. $${\left( {\sum {\text{V}} } \right)^2} + {\left( {\sum {\text{H}} } \right)^2}$$
B. $$\sqrt {{{\left( {\sum {\text{V}} } \right)}^2} + {{\left( {\sum {\text{H}} } \right)}^2}} $$
C. $${\left( {\sum {\text{V}} } \right)^2} + {\left( {\sum {\text{H}} } \right)^2} + 2\left( {\sum {\text{V}} } \right)\left( {\sum {\text{H}} } \right)$$
D. $$\sqrt {{{\left( {\sum {\text{V}} } \right)}^2} + {{\left( {\sum {\text{H}} } \right)}^2} + 2\left( {\sum {\text{V}} } \right)\left( {\sum {\text{H}} } \right)} $$
A. $${\text{a}} = \frac{\alpha }{{\text{r}}}$$
B. $${\text{a}} = \alpha {\text{r}}$$
C. $${\text{a}} = \frac{{\text{r}}}{\alpha }$$
D. None of these
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