Newton’s Second Law corrected the old belief that force is needed to maintain motion. This idea came from the philosopher:
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प्रश्न
A force of 10 N acts on a body of mass 2 kg for 3 s, initially at rest. Calculate : The velocity acquired by the body
योग
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उत्तर
Force, F = 10 N
Mass, m = 2 kg
Time, t = 3 s
Initial velocity, u = 0 m/s.
Let v be the final velocity acquired.
From Newton's second law,
F = ma.
Or, a = F/m = 10/2 = 5 ms-2.
From the 1st equation of motion,
a = (vu)/t
Or, v = at + u.
Or, v = (5)(3) + 0 = 15 m/s-1
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