Answer:
a) 20 m/s²
b) 0
Explanation:
average acceleration is, Vₙ - vₓ / Δt
where, Vₙ stands for final velocity,
Vₓ stands for initial velocity, and
Δt stands for change in time
according to the question,
for t₂, s = 2³ - 2² - 2 - 2 = 8 - 4 - 4 = 0
for t₄, s = 4³ - 4² - 4 - 2 = 64 - 16 - 8 = 64 - 24 = 40
substituting the values in the formulae,
average acceleration = 40 - 0 / 4 - 2 = 40/2 = 20 m/s²
when the velocity is 0 it indicates that acceleration will also be 0