AP EAMCET20224 Jul 2022Morning ShiftPhysicsMotion in One DimensionActual
A car covers a distance at speed of 60 km h - 1 . It returns and comes back to the original point moving at a speed of V . If the average speed for the round trip is 48 km h - 1 , then the magnitude of v is
Options
- A40   km   h - 1
- B36   km   h - 1
- C44   km   h - 1
- D32   km   h - 1
Correct answer
A. 40   km   h - 1
Step-by-step solution
Let car covers a distance of s in straight line from point A to B & then comes back to point A . Average speed = total distance covered total time taken . Now, time taken from A to B will be, s 60 . Time taken from B to A will be, s v . Therefore, 48 = s + s s 60 + s v ⇒ 1 60 + 1 v = 2 48 ⇒ 1 v = 1 24 - 1 60 ⇒ 1 v = 60 - 24 24 × 60 ⇒ v = 40   km   h - 1