Cara hitung nya gmna yhaa??

t1 = 10 s, S1 = 20 m
t2 = 20 s, S2 = 70 m
--------------------------------- +
Σt = 30 s, ΣS = 90 m


kecepatan rata-rata
v = ΣS / Σt
v = (90 m) / (30 s)
v = 3 m/s ← jwb

v bar = (x₁ + x₂) / (t₁ + t₂)
= (20 m + 70 m) / (10 s + 20 s) = 3 ms⁻¹