The area of parallelogram formed by vectors $\vec{P} = 2\hat{i} - \hat{j} + 5\hat{k}$ and $\vec{Q} = 3\hat{i} - 2\hat{j} + 4\hat{k}$ is

The percentage error in the measurement of mass of a body and its speed are $0.73\%$ and $1.84\%$ respectively. The percentage error in the measurement of its momentum and kinetic energy are respectively

A boat crosses a river from one bank A to another bank B which is opposite. The distance between them is D. The speed of water is $V_W$ and that of boat relative to water is $V_B$. If $V_B = 2V_W$, the time taken by the boat to cross the river directly along AB is $\left(\sin 30^\circ = \dfrac{1}{2}\right)$, $\left(\cos 30^\circ = \dfrac{\sqrt{3}}{2}\right)$

The weight of man in lift moving in upward direction with an acceleration 'a' is $660$ N. When the lift moves in the downward direction with the same acceleration, his weight is found to be $380$ N. The real weight of the man when the lift is at rest is