tolong bantu.............

Diket : t - 1,2 s
s = 210 m
v = 1400 m/s
ditny : t2
jwb : s = vt/2
210 m = 1400m/s (1,2 - t2) /2
1680 - 1400t2 = 420 m
1260 = 1400 t2
t2 = 1260/1400
t =0.9 s

Smoga Bermanfaat