If the ratio of densities of two substances is $5:6$ and the ratio of their specific heat capacities is $3:5$, then the ratio of heat energies required per unit volume so that the two substances can have the same temperature rise is

What is the main difference between the $P-T$ phase diagram of water and $CO_2$?

$A$ metal sphere immersed in water weighs $w_1$ at $0^{\circ} C$ and $w_2$ at $50^{\circ} C$. The coefficient of cubical expansion of the metal is less than that of water. Then

$A$ bullet of mass $5\, g$,travelling with a speed of $210\, m/s$,strikes a fixed wooden target. One half of its kinetic energy is converted into heat in the bullet while the other half is converted into heat in the wood. The rise of temperature of the bullet if the specific heat of its material is $0.030\, cal/(g \cdot ^{\circ}C)$ $(1\, cal = 4.2 \times 10^{7}\, ergs)$ is close to $.......^{\circ}C$.

$A$ closed bottle containing water at $30^{\circ}C$ is carried to the moon in a spaceship. If it is placed on the surface of the moon,what will happen to the water as soon as the lid is opened?

$A$ student takes $50 \, g$ of wax (specific heat $= 0.6 \, cal/g \cdot ^\circ C$) and heats it until it boils. The graph between temperature and time is shown below. The heat supplied to the wax per minute and the boiling point are respectively: