Answer:
We are given:
initial velocity (u) = 12 m/s
final velocity (v) = 0 m/s
time taken (t) = 15 seconds
acceleration (a) = a m/s²
Solving for acceleration:
from the first equation of motion
v = u + at
replacing the variables
0 = 12 + (a)(15)
0 = 15a + 12
a = -12 / 15
a = -4 / 5 m/s²