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A constant retarding force of 50 N is applied to a body of mass 20 kg moving initially with a speed of 15ms-¹. How long does the body take to stop? |
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Answer» Force : F=50N ; Mass : m=20kg ; Initial velocity : u=15m/s From newton’s second law, F=ma 50=20×a a=2.5m/s2 From equations of motion , v=u+at 0 =15+(−2.5)t Solve to get : t = 6s Hence, the body will be stop in 6 seconds F= 50Nm = 20Kg therefore , a= F/m = 50/20 = 2.5 using v = u + at 0= 15 - 2.5(t) t= 6sec. |
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