Tolong bantuannya nomor 1 dan 2 Terimakasih kak

1.
Dik :
vo = 90 km/jam = 25 m/s
a = - 8 m/s^2
s = 21
Dit: t

Jawab:
GLBB
vt^2 = vo^2 + 2.a.s
vt^2 = 25^2 + 2(-8).21
vt^2 = 625 - 336
vt^2 = 289
vt = 17 m/s

vt = vo + a.t
17 = 25 + (-8).t
8t = 8
t = 1 sekon


2.
Dik :
vo = 25 m/s
s = 500 m
vt = 10 m/s
Dit: a

Jawab:
vt^2 = vo^2 + 2as
10^2 = 25^2 + 2.a.500
100 = 625 + 1000a
1000a = -525
a = -0,525 m/s^2 (tanda min berarti diperlambat)