An object,moving with a speed of $6.25\, m/s$,is decelerated at a rate given by $\frac{dv}{dt} = -2.5\sqrt{v}$,where $v$ is the instantaneous speed. The time taken by the object to come to rest would be ........ $s$.

If $\omega$ is a complex cube root of unity,then $225+(3 \omega+8 \omega^2)^2+(3 \omega^2+8 \omega)^2$ is equal to:

The decay rate for a certain mass of a radioactive substance measured at different times varies with time as shown in the figure. The count rate at $t = 8 \, hr$ will be:

The radiant energy from the sun incident normally at the surface of the earth is $20 \ kcal/m^2-min$. What would have been the radiant energy incident normally on the earth if the sun had a temperature twice of the present one? (in $kcal/m^2-min$)

The hydroxides and carbonates of sodium and potassium are easily soluble in water,while the corresponding salts of magnesium and calcium are sparingly soluble in water. Explain.

How many bridging oxygen atoms are present in $P_4O_{10}$?