The figure shows the cross-section of a conical flask having a circular base of diameter 0.20 m . The slanted surface of the cone makes an angle of $60^{\circ}$ with the base. When 2.0 litres ( 1 litre $=10^{-3} \mathrm{~m}^3$ ) of water is poured in the flask, the level of water is 0.25 m above the base.


What is the magnitude of the total vertical force exerted by the water on the slanted surface of the flask? (Take acceleration due to gravity $g=10 \mathrm{~ms}^{-2}$ and ignore atmospheric pressure.)

• A

  0 N
• B

  20.0 N
• Correct answer
  C

  58.5 N
• D

  78.5 N

Hence, the correct answer is option: 'C'.