Q.

If force [F], acceleration [A] and time [T] are chosen as the fundamental physical quantities, find the dimensions of energy.                   [2021]

1 [F][A-1][T]  
2 [F][A][T]  
3 [F][A][T2]  
4 [F][A][T-1]  

Ans.

(3)

Let for energy, [E]=FαAβTγ

or [M1L2T-2]=[MLT-2]α[LT-2]β[T]γ

M1L2T-2=MαLα+βT-2α-2β+γ

Comparing from both sides, α=1

α+β=2β=1

-2α-2β+γ=-2γ=2  Energy=[F][A][T2]