A sample of metal weighs 219 gms in air, 180 gms in water, 120 gms in an unknown fluid. Then which is correct statement about density of metal

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 framed structure is perfect, if the number of members are __________ (2j - 3), where j is the number of joints.

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. $$\sqrt {{{\left( {\sum {\text{V}} } \right)}^2} + {{\left( {\sum {\text{H}} } \right)}^2} + 2\left( {\sum {\text{V}} } \right)\left( {\sum {\text{H}} } \right)} $$

The linear acceleration (a) of a body rotating along a circular path of radius (r) with an angular acceleration of $$\alpha $$ rad/s², is

A. $${\text{a}} = \frac{\alpha }{{\text{r}}}$$

B. $${\text{a}} = \alpha {\text{r}}$$

C. $${\text{a}} = \frac{{\text{r}}}{\alpha }$$

D. None of these