A \(50\) kg girl wearing high heel shoes balances on a single heel. The heel is circular with a diameter of \(1.0\) cm. What is the pressure exerted by the heel on the horizontal floor?
1. \( 6.24 \times 10^6 ~\mathrm{Nm}^{-2} \)
2. \( 4.21 \times 10^5 ~\mathrm{Nm}^{-2} \)
3. \( 20 \times 10^6 ~\mathrm{Nm}^{-2}\)
4. \( 1.01 \times 10^5~ \mathrm{Nm}^{-2}\)
Toricelli’s barometer used mercury. Pascal duplicated it using French wine of density \(984~\text{kg/m}^3.\) The height of the wine column for normal atmospheric pressure is:
1. \(11.5~\text{m}\)
2. \(10.5~\text{m}\)
3. \(9.00~\text{m}\)
4. \(15.0~\text{m}\)
A hydraulic automobile lift is designed to lift cars with a maximum mass of \(3000\) kg. The area of the cross-section of the piston carrying the load is \(425\) cm2. What maximum pressure would the smaller piston have to bear?
1. \(3.12\times10^{5}\) Pa
2. \(1.01\times10^{5}\) Pa
3. \(2.94\times10^{5}\) Pa
4. \(6.92\times10^{5}\) Pa
A U-tube contains water and methylated spirit separated by mercury. The mercury columns in the two arms are in level with 10.0 cm of water in one arm and 12.5 cm of spirit in the other. What is the specific gravity of the spirit?
1. 0.8
2. 0.3
3. 0.5
4. 0.7
A tank with a square base of an area of 1.0 m2 is divided by a vertical partition in the middle. The bottom of the partition has a small-hinged door of area 20 cm2. The tank is filled with water in one compartment, and an acid (of relative density 1.7) in the other, both to a height of 4.0 m. What is the force necessary to keep the door close?
1. 54.88 N
2. 56.0 N
3. 60.0 N
4. 45.5 N
During a blood transfusion, the needle is inserted in a vein where the gauge pressure is \(2000\) Pa. At what height must the blood container be placed so that blood may just enter the vein?
(The density of whole blood is \(1.06\times10^{3}\) kg/m3).
1. \(0.163\) m
2. \(0.192\) m
3. \(0.157\) m
4. \(0.754\) m