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Question Question 6(ii)
(a) How a beam balance comes to static equilibrium?
(b) How a plane moves at a constant height? On which fact it is based?
(a) In beam balance when the beam is balanced in a horizontal position, it is in static equilibrium. The clockwise and anticlockwise moments balance each other hence the beam has no rotational motion and it is in static equilibrium.
(b) A plane moves at a constant height when upward lift on it balances its weight acting downwards. It is due to dynamic equilibrium of forces.