Nomor Empat. A, B, Dan C

a)
sigma F = 0
N - wy = 0
N = wy
N = mg cos teta
N = 400 cos 30
N = 200 akar 3

b)
sigma F = 0
N - Ftekan - wy = 0
N = F tekan + wy
N = 100 akar 3 + 200 akar 3
N = 300 akar 3