Giai gium minh.
Mot oto tai 4 banh co khoi luong 15 tan cho 30 thung hang,biet moi thung hang nang 60 kg.Dien tich cua mot banh xe oto la 12 dm2.
a)tinh ap suat oto tac dung len mat duong?
b)De ap suat tac dung len mat duong la 335000N/m2 thi phai bo xuong khoi xe bao nhieu thung hang?{biet dien tich tiep xuc cua cac banh xe voi mat duong khong doi}