Average acceleration of the particle during the 2.4 s interval is -20 m/s²
Step-by-step explanation:
We have equation of motion v = u + at
Initial velocity, u = 18 m/s
Final velocity, v = -30 m/s
Time, t = 2.4 s
Substituting
v = u + at
-30 = 18 + a x 2.4
a = -20 m/s²
Acceleration is -20 m/s²
Average acceleration of the particle during the 2.4 s interval is -20 m/s²