确实是4.8m/s
W总=Pt=9.6X104WX100s=9.6X106J
W有=W总X80%=7680000J
W有=Gh
h=W有/G=7680000J/3.2X104=240m
∵斜坡为30°
∴斜坡长=240m/sin(30°)=480m
v=s/t=480m/100s=4.8m/s
望采纳.
确实是4.8m/s
W总=Pt=9.6X104WX100s=9.6X106J
W有=W总X80%=7680000J
W有=Gh
h=W有/G=7680000J/3.2X104=240m
∵斜坡为30°
∴斜坡长=240m/sin(30°)=480m
v=s/t=480m/100s=4.8m/s
望采纳.