Question

The velocity v of a particle at time t is given by v =  at+b/t+c,where a, b and c are constants. The dimensions of a, b and c are

(a) [L],[LT] and [LT^-2]

(b) [LT^-2], [L] and [T]

(c) [L²], [T] and [LT^-2]

(d) [LT^-2], [LT] and [L]

Answer 1

Answer: (b) [LT^-2], [L] and [T]

According to the principle of dimensional homogeneity

Dimension of v = dimension of at = dimension of \(\frac{b}{t+c}\)

Dimension of a =\(\frac{\mathrm{[v]}}{[t]}=\frac{LT_2}{T}=[LT^{-2}]\)

Dimension of b =[v][t]=[LT-1T]=[L]

Dimension of c = [t]=[T]

Answer 2

Correct Option  (b) [LT^-2], [L] and [T]

Explanation: 

v = at+ b/t+c

As c is added to t,

:. [c] = [T]