Question

The velocity of water flowing in a non-uniform tube is 20 cm/s at a point where the tube radius is 0.2 cm. The velocity at another point, where the radius is 0.1 cm, is

• A. 80 cm/s
• B. 40 cm/s
• C. 20 cm/s
• D. 5 cm/s

Answer 1

Answer: (A)

80 cm/s

Answer 2

In now of fluids in a tube ${{v}_{1}}r_{1}^{2}={{v}_{2}}r_{2}^{2}$ $20\times {{(0.2)}^{2}}={{v}_{2}}\times {{(0.1)}^{2}}$ ${{v}_{2}}=\frac{20\times {{(0.2)}^{2}}}{{{(0.1)}^{2}}}$ ${{v}_{2}}=80\,\,cm/s$