Consider an object is placed on a frictionless inclined plane at a height of 5m, if it is released, what will be its velocity at the bottom of the inclined plane?
Correct answer: B. 10 m/s
- A. Insufficient information
- B. 10 m/s
- C. 100 m/s
- D. 20 m/s
Explanation
We shall need to assume that friction and air resistance are to be ignored. We are also not told the mass of the object or the angle of the inclined plane, but it will turn out that we can form an answer anyway. We shall also assume that the experiment is done in normal earth-surface gravity.Let's call the mass of the object m and the speed of the object at the bottom of the ramp The object's kinetic energy at the top of the ramp is zero, and at the bottom of the ramp it is 12mv2.The object's potential energy (relative to the bottom of the ramp) at the top of the ramp is mgh, where h=5m is the height the object is released from and g≈9.81ms−2 is the acceleration due to gravity, and at the bottom of the ramp it is zero.By conservation of energy we have
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