A physical quantity Q is found to depend on quantities x, y, z obeying relation Q \(={{x^2y^3}\over{z^1}}.\) The percentage errors in x, y and z are 2%, 3% and 1% respectively. Find the percentage error in Q.

Calculate the number of times a human heart beats in the life of 100 years old man. Time of one heart beat = 0.8s.

Check the correctness of the following equation using dimensional analysis. Make a comment on it. S = ut + 1/4at² where s is the displacement, u is the initial velocity, t is the time and a is the acceleration produced.

The velocity of a body is given by the equation v = b/t + ct² + dt³. Find the dimensional formula for b.

The voltage across a wire is (100 ± 5)V and the current passing through it is (10 ± 0.2) A. Find the resistance of the wire.