Cau 1: Khi noi cong suat xe tai la 30000W, con so 30000W cho ta biet dieu gi? Cau 2: Nguoi ta dung 1 mat phang nghieng de keo 1 vat co khoi luon

Cau 1:
Khi noi cong suat xe tai la 30000W, con so 30000W cho ta biet dieu gi?
Cau 2:
Nguoi ta dung 1 mat phang nghieng de keo 1 vat co khoi luong 50kg len cao 2m. Neu khong co luc ma sat thi luc keo la 125N.
a) Tinh cong nang vat len theo phuong thang dung
b) Tinh chieu dai cua mat phang nghieng?
c) Trong thuc te co luc ma sat va luc keo vat la 150N. Tinh hieu suat cua mat phang nghieng?