看不到图,猜测应该是两股绳子拉物体:
有用功:W有=Gh
=100h
总功:W总=FS
=75S
因为是两段绳子,所以:s=2h
机械效率为:
η=W有/W总
=Gh/FS
=100h/75×2h
=100/150
=66.67%
答:机械效率为66.67%.
看不到图,猜测应该是两股绳子拉物体:
有用功:W有=Gh
=100h
总功:W总=FS
=75S
因为是两段绳子,所以:s=2h
机械效率为:
η=W有/W总
=Gh/FS
=100h/75×2h
=100/150
=66.67%
答:机械效率为66.67%.