Jawablah pertanyaan di bawah menggunakan cara !

nomor 7, jawabannya B
W = F x s
=(400+150-200) x 15
= 350 x 15 = 5250

nomor 8, jawabannya D
Qab = m . c . t
= 5 x 4200 x (100-30)
= 1.470.000
[tex] = 1.47 \times {10}^{6} [/tex]

Qbc = m . U
=5 x 22,6. 10^6
[tex] = 113 \times {10}^{6} [/tex]

jadi kalor seluruhnya
[tex] = 113 \times {10}^{6} + 1.47 \times {10}^{6} \\ = 114.47 \times {10}^{6} [/tex]

maaf kalo salah

jawab :

7).
W = F × s
= (400+150-200) . 15
= (350) . 15
= 5.250 J (B)

8).
dik : C.air = 4200 J/kg°C
U = 22,6 × 10^6 J/kg = 22.600.000 J/kg
∆t = 100-30 = 70°C
m = 5 kg
Q = _____??

jawab:
Qab= m × C.air × ∆t
= 5 × 4.200 × 70
= 1.470.000 J

Qbc = m × U
= 5 × 22.600.000
= 113.000.000 J

Q.gab = 1.470.000 + 113.000.000
= 114.470.000
= 114,47 = 10^6 J (D)

semoga bermanfaat......