tolong bantu ya no 2 4 5

2)
fa=vb×pair×g
fa=20×1000×9.8
fa=196.000
4)
s=v×t÷2
s=349×2÷2
s=680÷2
s=340
5)
1/f=1/s+1/s'
1/15 = 1/10+1/s'
1/s'=1/10-1/15
1/s'=2-3/30
1/s'=1/30
1/s'=30