When an object moving in a straight line with uniform acceleration passes through points a, B and C in turn, it is known that ab = BC, and the average velocities of AB and BC sections are V1 = 3m / s and V2 = 6m / s respectively (1) What are the instantaneous velocities VA, VB and VC of an object passing through points a, B and C? Why can't we use the simultaneous formula (VA + VB) / 2 = 3, (VB + VC) / 2 = 6, (VA + VC) / 2 = VB to calculate VB equal to 4.5? Please tell me why it's not right to do so

The formula (VA + VC) / 2 = VB is wrong. Half of the initial and final velocity is the instantaneous velocity at the middle point of time, not the instantaneous velocity at the distance from the middle point

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1. When an object moving in a straight line with uniform acceleration passes through points a, B and C in turn, the displacement XAB = XBC. It is known that the average velocity of the object in AB section is 3m / s, and that in BC section is 6m / s, then the instantaneous velocity of the object at point B is () A. 4 m/sB. 4.5 m/sC. 5 m/sD. 5.5 m/s
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