Sebuah mobil melaju dengan kecepatan 54 km/jam - 72 km/jam. jika massa mobil 800 kg, berapa usaha yang diperlukan mobil tersebut ?
liliput01
Diket: v1 = 54km/jam = 54000m/3600s = 15m/s v2 = 72km/jam = 72000m/3600s = 20m/s m = 800 kg Dit: Usaha (W)....? W = perubahan energi kinetik W = ΔEk = 1/2 m (v2² - v1²) W = 1/2 x 800 x (20² - 15²) W = 400 x (400 - 225) W = 400 x 175 W = 70.000 J atau W = 70 kJ
v1 = 54km/jam = 54000m/3600s = 15m/s
v2 = 72km/jam = 72000m/3600s = 20m/s
m = 800 kg
Dit: Usaha (W)....?
W = perubahan energi kinetik
W = ΔEk = 1/2 m (v2² - v1²)
W = 1/2 x 800 x (20² - 15²)
W = 400 x (400 - 225)
W = 400 x 175
W = 70.000 J
atau W = 70 kJ