1) from the functions of levers ......... a) increase effort b) increase the force c) make the life more difficult  2) The fixed point in the lever is called ...... a) Fulcrum b) effort force c) Resistance force 3) ......... level always conserves effort a) second class b) third class c) first class 4) the third class levers .......... effort a) save b) don't save c) sometimes save 5) when the force arm is smaller than the resistance arm this lever may be ......... class lever a) first or second b) first or third c) second or third d) second only e) third only f) first only 6) In a third-class lever, the force arm equals 30 m and the resistance arm equals 50m, and the force which is used to equilibrate the resistance equals 80N so what is the resistance force a) 50N b) 48N c) 68N d) 46N e) 60N f) 80N

levers

打印
嵌入

排行榜

视觉风格

选项

切换模板

恢复自动保存：？