Question

A car starts from rest and again comes to rest after trav-
elling a distance of 12 km in 1/8 hour. Its maximum velocity in between is 120km/h. In its journey, accelera-
tion and retardation are both uniform, and the value of
acceleration is half that of retardation. How long does
the car travel with uniform velocity?
ans is [4.5 min).
please solve in correct way don't give wrong answer. ​

Answer 1

Answer:

Okay, let's write the given data.

Acceleration (α) = ½ Retardation (β) [α=½β OR 2α=β] ----- (1)

Distance (s) = 12 Km ⇒ 12000 m [Convert Km into m]

Maximum velocity (v₁) = 120 Km⁻¹ ⇒ (100/3)ms⁻¹

Time (t₁) = 1/8th of an hour ⇒ 7.5 minutes.

Time of car travel (t₂)

initial velocity (u) = 0

Final velocity (v) = 0

THEN, use this formula:

v₁  =αt₁ =(β+α )÷(αβt₂ )

HOPE THIS HELPS :D