Which equation is not dimensionally correct ?
Correct answer: C. S=Vt2
- A. E=mc2
- B. Vf=Vi+at
- C. S=Vt2
- D. S=1/2at2
Explanation
In S = Vt², the right side has dimensions (m s^-1)(s²) = m s, which is not a length. The other equations have length on both sides, so students often select d because they overlook the factor 1/2 rather than checking dimensions.
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The work-energy theorem states that the net work done on an object equals its change in kinetic energy. Questions involve positive and negative work, variable forces and force-displacement graphs, acceleration or deceleration, and the difference between this theorem and conservation of mechanical energy, which also requires attention to potential energy and non-conservative work.
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