The heart of a man pumps \(5~\text{L}\) of blood through the arteries per minute at a pressure of \(150~\text{mm}\) of mercury. If the density of mercury is \(13.6\times10^{3}~\text{kg/m}^{3}\)$$ $\mathrm{and}{\mathrm{}}^{}$ \(g = 10~\text{m/s}^2,\) then the power of the heart in watts is:

A \(U\text-\)tube with both ends open to the atmosphere is partially filled with water. Oil, which is immiscible with water, is poured into one side until it stands at a level of \(10~\text{mm}\) above the water level on the other side. Meanwhile, the water rises by \(65~\text{mm}\) from its original level (see diagram). The density of the oil is: 
                
1. \(425~\text{kg m}^{-3}\)
2. \(800~\text{kg m}^{-3}\)
3. \(928~\text{kg m}^{-3}\)
4. \(650~\text{kg m}^{-3}\)

A barometer kept in a stationary elevator reads \(76 ~\text{cm}.\) If the elevator starts accelerating up, the reading will be:
1. zero
2. equal to \(76 ~\text{cm}\)
3. more than \(76 ~\text{cm}\)
4. less than \(76 ~\text{cm}\)

In a U-tube, as shown in the figure, the water and oil are in the left side and right side of the tube respectively. The height of the water and oil columns are \(15~\text{cm}\) and \(20~\text{cm}\) respectively. The density of the oil is: 
 \(\left[\text{take}~\rho_{\text{water}}= 1000~\text{kg/m}^{3}\right]\)$$

              
1. \(1200~\text{kg/m}^{3}\)
2. \(750~\text{kg/m}^{3}\)
3. \(1000~\text{kg/m}^{3}\)
4. \(1333~\text{kg/m}^{3}\)

A man of mass \(75\) kg lies on a bed of \(10000\) nails. The tip of each nail has an area of \(1.0\) square millimetres. What pressure does the man experience? (Take \(g=10\) N/kg)
1. $7.5\times {10}^6$ pa
2. $7.5\times {10}^4$ Pa
3. $7.5\times {10}^3$ Pa
4. $7.5\times {10}^7$ Pa