If mass-energy equivalence is taken into account,when water is cooled to form ice,the mass of water should

Bell metal is an alloy of which of the following?

If $x=a\left[\cos \theta+\log \left\{\tan \left(\frac{\theta}{2}\right)\right\}\right]$ and $y=a \sin \theta$,then $\frac{dy}{dx}$ is equal to

If $\lim _{x \rightarrow \infty}\left(\frac{x^2+x+1}{x+1}-ax-b\right)=4$,then

$A$ conveyor belt is moving at a constant speed of $2\, m/s$. $A$ box is gently dropped on it. The coefficient of friction between them is $\mu = 0.5$. The distance that the box will move relative to the belt before coming to rest on it,taking $g = 10\, m/s^2$,is ........ $m$.