JEE Main202225 Jun 2022Evening ShiftPhysicsMotion in One DimensionActual
Two buses P and Q start from a point at the same time and move in a straight line and their positions are represented by x P t = α t + β t 2 and x Q t = f t - t 2 . At what time, both the buses have same velocity ?
Options
- Aα - f 1 + β
- Bα + f 2 β - 1
- Cα + f 2 1 + β
- Df - α 2 1 + β
Correct answer
D. f - α 2 1 + β
Step-by-step solution
As we know, v = d x d t . Given, x P t = α t + β t 2 Velocity of bus P is v P = d x P d t = α + 2 β t and velocity of bus Q is v Q = f - 2 t When v P = v Q ⇒ α + 2 β t = f - 2 t ⇒ f - α = 2 β + 1 t   ⇒ t = f - α 2 β + 1