Bantuin dongfisika tentang usaha dan energi

1 a. Vt =V0+at = 20+(0,2×20)= 20+4 = 24 m/s
b. Ek awal = 1/2 m x v0^2  = 1/2 x 1 x 20^2 = 200 J
    Ek akhir = 1/2 m x vt^2 = 1/2 x 1 x 24^2 =288 J

c. Usaha (W)=perubahan energi kinetik = 288-200=88 J

2. W = 1/2 x m x v^2 = 1/2 x 1000 x 20^2 = 200000 Joule = 200 kJ

ket: 1 ton =1000 kg