A 05-Kg Model Helicopter Initially at Rest on the Ground,starts to to Move

question 58

Multiple Choice

A 0.5-kg model helicopter initially at rest on the ground,starts to move directly up under the effect of a lift force of magnitude of 7.4 N.After 12 seconds the engine stops and the helicopter starts free fall.Ignoring air resistance,calculate the helicopter's velocity just as the engine stops.

• A)59.9 m/s
• B)178 m/s
• C)48.4 m/s
• D)38.0 m/s
• E)118 m/s

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Definitions:

Marginal Benefit

The extra benefit or pleasure that someone receives from using an additional unit of a specific good or service.

Marginal Cost

The increase in cost resulting from the production of one additional unit of a good or service.

Marginal Benefit

The extra utility or satisfaction that is derived from the consumption or manufacture of one more unit of a good or service.

Marginal Cost

The growth in complete cost caused by the manufacture of one more unit of a good or service.