Assume that the cross section of the artery of human is circular. A drug is given to a patient to dilate his arteries. If the radius of an artery is increased from 2 mm to 2.1 mm, how much is cross-sectional area increased approximately?

Let us assume that the the the shape of a soap bubble is a sphere . Use linear approximation to approximate the increase in the surface area of a soap bubble as its radius increases from 5 cm to 5.2 cm also calculate the percentage error.

Two wires are made of the same material and have the same volume. The area of cross sections of the first and the second wires are A and 2A respectively. If the length of the first wire is increased by Delta l on applying a force F, how much force is needed to stretch the second wire by the same amount ?

A circular metal plate expands under heating so that its radius increases by 2%. Find the approximate increase in the area of the plate if the radius of the plate before heating is 10 cm.

A heater coil is to be constructed with a nichrome wire (rho = 1.0 xx 10^(-6) Omegam) which can operate at 500 W when connected to a 250 V supply. (a) What would be the resistance of the coil? (b) If the cross-sectional area of the wire is 0.5 mm^2 , what length of the wire will be needed? (c) If the radius of each turn is 4.0 mm , how many turns will be there in the coil?

A horizontal pipe line carries water in a streamline flow. At a point along the pipe where the cross-sectional area is 10cm^(2) the velocity of water is 1 ms^(-1) and pressure is 2000 Pa. What is the pressure at another point. Where the cross-sectional area is 5cm^(2) ?