An object has an initial velocity of 15 m/s. How long must it accelerate at a constant rate of 3.0 m/s^2 before its final velocity is equal 30 m/s?

v=u + at

V= Final velocity =30m/s

U= initial velocity = 15m/s

a= acceleration = 3m/s^2

t= time taken

t=(v-u)/a

t=(30-15)/3

t=5s

Explanation:

find the sum of the two horizontal vectors and the sum of the two vertical vectors

isoceles right angled triangle