The cylindrical tube of a spray pump has a radius \(R,\) one end of which has \(n\) fine holes, each of radius \(r.\) If the speed of the liquid in the tube is \(v,\) the speed of the ejection of the liquid through the holes is:
1. \(\frac{vR^{2}}{n^{2}r^{2}}\)

2. \(\frac{vR^{2}}{nr^{2}}\)

3. \(\frac{vR^{2}}{n^{3}r^{2}}\)

4. \(\frac{v^{2}R}{nr}\)

An ideal fluid flows through a pipe of circular cross-section made of two sections with diameters \(2.5\) cm and \(3.75\) cm. The ratio of the velocities in the two pipes is:
1. \(9:4\)
2. \(3:2\)
3. \(\sqrt{3}:\sqrt{2}\)
4. \(\sqrt{2}:\sqrt{3}\)

Water enters through end \(A\) with a speed \(v_1\) and leaves through end \(B\) with a speed \(v_2\) of a cylindrical tube AB. The tube is always completely filled with water. In case I the tube is horizontal, in case II it is vertical with the end \(A\) upward and in case III it is vertical with the end \(B\) upward. We have \(v_1=v_2\) for:
1. case I
2. case II
3. case III
4. each one