JEE Main202125 Jul 2021Evening ShiftPhysicsMotion in One DimensionActual
The instantaneous velocity of a particle moving in a straight line is given as v = α t + β t 2 , where α and β are constants. The distance travelled by the particle between 1 s and 2 s is:
Options
- A3 α + 7 β
- B3 2 α + 7 3 β
- Cα 2 + β 3
- D3 2 α + 7 2 β
Correct answer
B. 3 2 α + 7 3 β
Step-by-step solution
V = α t + β t 2 d s d t = α t + β t 2 ∫ S 1 S 2   d s = ∫ 1 2 α t + β t 2 d t S 2 - S 1 = α t 2 2 + β t 3 3 1 2 As the particle is not changing direction So distance = displacement. Distance = α [ 4 - 1 ] 2 + β [ 8 - 1 ] 3 = 3 α 2 + 7 β 3