Bantui tugas fisika aku yaa.. Besok di kumpul Makasihh

1. a = 4 m/s²
a. vo = 3 m/s
t = 7 s
v = vo + at = 3 + (4)(7) = 3 + 28 = 31 m/s
b. a = - 4 m/s²
v = vo + at
v = 3 + (-4)(7) = 3 - 28 = -25 m/s

2. x = 70 m, t = 7 s, vo = 15 m/s
kelajuan benda
v = x/t = 70/7 = 10 m/s
percepatan benda
a = (v - vo)/t
a = (10 - 15)/7 = -5/7 = -0.71 m/s² (diperlambat)

3. gerak pertama
vo = 0, a = 4 m/s², t = 10 s
x1 = ½at² = ½(4)(10)² = 200 m

gerak kedua
v = at = 4 x 10 = 40 m/s
t = 10 s
x2 = v t = 40 (10) = 400 m

gerak ketiga
a = -8 m/s²
vo = 40 m/s
v = 0
v² = vo² + 2a(x3)
0 = (40)² + 2(-8)(x3)
0 = 1600 -16(x3)
16(x3) = 1600
x3 = 100 m

maka jarak totalnya adalah
Σx = x1 + x2 + x3 = 200 + 400 + 100 = 700 m