math
posted by raj .
a car travels around a horizontal circular track of radius 45m. if the car increases its speed at a constant rate of 1.2m/s starting from rest, determine the time needed for it to reach an acceleration of 1.4m/s. What is its speed at this instant?

speed increases at a rate of 1.2m/s/?
If the speed increases, the value (m/s) increases by 1.2m.s every how often?
acceleration is not measured as m/s.
It looks to me like you should have written the acceleration is 1.2m/s^2, and you want to find how long it takes the speed to get to 1.4m/s.
That would be 1.4/1.2 seconds.
Naturally, at that time, the speed is 1.4m/s.
If I got it wrong, clarify and repost.