Question

In an opencast coal mine, blast vibrations are measured at two locations, A and B simultaneously for a maximum charge per delay (Q) of 1200 kg as given.

Location	Distance from the blast face, D (m)	PPV (mm/s)
A	100	112.5
B	300	20.3

\(PPV=K[\frac{D}{\sqrt{Q}}]^{-B}\)
where, K and ẞ are site constants. The PPV in mm/s, at a distance of 200 m from the blast face, is (round off up to 2 decimals) 

Answer 1

Correct Answer: 37.5

The correct answer is: 37.50 or 38.50 (approx)