The power is the dot product of ___________ quantities.
Correct answer: B. Force and velocity
- A. Force and time
- B. Force and velocity
- C. Force and speed
- D. None of these
Explanation
Mechanical power is the rate of doing work: P = F · v = Fv cosθ, so it is the dot product of force and velocity. Speed has no direction, so force and speed cannot form a vector dot product, although power can equal force times speed when the force is along the motion. Students may choose force and speed because this simplified formula is often used without mentioning the direction condition.
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About Power
Power is the rate at which work is done or energy is transferred, with average power calculated over a time interval and instantaneous power found from P = Fv when force and velocity are aligned. Work includes units, mechanical efficiency, and the distinction between power and total work or energy.
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