An object of mass 2kg has a velocity of 6m/s. After 8 seconds, its velocity increases to 10m/s. Calculate the power of the object
Correct answer: C. 8 watts
- A. 10 watts
- B. 5 watts
- C. 8 watts
- D. 9 watts
Explanation
Power is defined as the rate of doing work.Power = Work Done / TimeWork done is defined as the change in kinetic energy.Work = 1/2 * m * (v^2 - u^2)Where:m = mass of the objectv = final velocityu = initial velocityIn this case, the initial velocity u = 6m/s, the final velocity v = 10m/s, and the mass m = 2kg.Therefore, the work done is:Work = 1/2 * 2 * (10^2 - 6^2) = 64 JThe time taken is 8 seconds.Therefore, the power is:Power = 64 J / 8 s = 8 watts
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About Work and Energy
Work transfers energy when a force causes displacement, while kinetic energy, gravitational potential energy and power describe motion, position and the rate of energy transfer. The work-energy theorem links net work with change in kinetic energy, and efficiency accounts for energy losses rather than treating them as energy destruction.
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