Two capillary tubes with inside diameters of 1.20 mm and 0.70 mm, respectively, are inserted into a liquid of density 0.87 g.cm-3. Calculate the surface tension of the liquid if the difference between the capillary rises in the tubes is 1.4 cm. Assume the contact angle is zero. A hypodermic syringe is filled with a solution of viscosity 1.4x10-3 N.s.m-2. The plunger area of the syringe is 7.6x10-5 m2, and the length of the needle is 0.025 m. The internal radius of the needle is 4.2x10-4 m. The gauge pressure in a vein is 1733 Pa (13.0 mmHg). Calculate the force in newtons that must be applied to the plunger so that 1.2x10-6 m3 of the solution can be injected in 4.2 s