Answer:
3 seconds
Explanation:
From the question above,
we can apply the first equation of motion which is,
a = (v-u)/t.................... Equation 1
Where a = acceleration. v = final velocity, u = initial velocity, t = time.
make t the subject of the equation
t = (v-u)/a.............. Equation 2
Given: a = -3 m/s²(decelerating), u = 9 m/s, v = 0 m/s (to stop)
substitute these values into equation 2
t = (0-9)/-3
t = -9/-3
t = 3 seconds
