dijawab yaa ini soal yg tdi nggk ada itu...

No 3.
Usaha total
Wtotal = luas 1 + Luas 2 + luas 3 + luas 4

*Luas 1 (trapesium) = (1+4). 2 / 2= 5 joule
*luas 2 (trapesium) = (4+6) .4 / 2= 20 Joule
*luas3 (segitiga) = 1/2 . 2 . (-4) = -4 joule
*luas 4 (trapesium) = (4+6). (-4) /2 = -20 joule

Wtotal = 5 + 20 - 4 - 20 = 1 joule


no.4
usaha masing2 anak
*anak 1
W1 = F1 . s
W1 = -260 N . 5 m
W1 = -1300 joule
(nilai min.karena arah F berlawanan arah dgn arah perpindahan s)

*anak2
W2 = F2 . s
W2 = 300 N . 5 m
W2 = 1500 Joule

Wtotal = W1 + W2
Wtotal = -1300 + 1500 Joule
Wtotal = 200 joule

no.5
W1 = F1.cos 30° . s
W1 = 180 . 1/2 akar 3 . 16
W1 = 1440 akar3
W1 = 2494,15 joule

W2 = F2.cos60 . s
W2 = 180 . 1/2 . 16
W2 = 1440 joule

Wtotal = W1 + W2
Wtotal = 2494,15 + 1440 joule
Wtotal = 3934,15 Joule