A particle moving with constant acceleration has speed 10 m s⁻¹ at x=0 and 30 m s⁻¹ at x=2D, without reversal. Its speed at x=D is:
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A particle moving with constant acceleration has speed 10 m s⁻¹ at x=0 and 30 m s⁻¹ at x=2D, without reversal. Its speed at x=D is:

G1 Physics · Accepted Answer

For constant acceleration, v² = u² + 2ax. At x=2D, 30² = 10² + 4aD ⇒ 800 = 4aD ⇒ aD=200. At x=D, v² = 10² + 2aD = 100+400 = 500. Hence v = 10√5 m s⁻¹.