The answer is A. subduction
<span>The Richter measures multiple sources of energy being released while the Mercalli measures energy released from the epicenter or focus.</span>
Answer:
Explanation:
Given
Weight of helicopter 
inclination of blades with vertical 
Suppose
is the lifting Force
Now using F-B-D
as helicopter is moving with constant velocity
balancing forces in Vertical Force





Now sin component of lift is air resistance

where R=air resistance


