题型:问答题 简答题 Generally speaking, if ______ strictly following the instructions, the electric bike is not as dangerous as reported.A.ridingB.being riddenC.to be riddenD.ridden 查看答案
题型:问答题 简答题 如图所示(滑轮组的绕绳未画出),人以600N的力向下拉动绕在滑轮组的绳子一端,10秒使绳端向下移动了1.5m、重物匀速上升了0.5m,已知滑轮组的机械效率为80%(g=10N/kg).请按题意画出滑轮组的绕绳.并计算人的拉力的功率是_________W,重物为_________ N。 查看答案