A through hole is drilled in an aluminium alloy plate of

A through hole is drilled in an aluminium alloy plate of 15 mm thickness with a drill bit of diameter 10 mm, at a feed of 0.25 mm/rev and a spindle speed of 1200 rpm. If the specific energy required for cutting this material is 0.7 N-m/ mm³, the power required for drilling is ___ W (round off to two decimal places).

Power required, P = S × Q
Where S = specific power = 0.7 N-m/mm³

Q = MRR =	π D²	× f × N
	4

=	π × (10)²	× 0.25 ×	1200	= 125π mm³/sec
	4		60

Power, P = 0.7 × 125π
P = 274.889 W ≈ 274.89 W