本课配套习题挑战模式1/5
用如图所示的滑轮组匀速提升一个重为G的物体,不计摩擦和滑轮的重力,则拉力F的大小是( )
A: |
B: |
C: |
D: G |
- 提示1:PHA+5Yqo5ruR6L2u55yB5Yqb77yM5ouJ5Yqb5bCP5LqORzwvcD4=
- 提示2:PHA+5Lik6IKh57uz5a2Q5ouJ5LiL6Z2i54mp5L2TPC9wPg==
- 提示3:PHA+5ouJ5YqbRuetieS6jjEvMkc8L3A+
- 答案:Qg==
PGRpdj7liqjmu5Hova7nnIHlipvvvIzmnInkuKTogqHnu7PlrZDmi4nkuIvpnaLniankvZPvvIzmr4/ogqHnu7PlrZDmi4nlipvkuLpG77yMMkY9R++8jEY9MS8yR+OAgjwvZGl2Pg==
本课配套习题挑战模式2/5
使用如图所示的装置来提升物体时,既能省力又能改变力的方向的装置是( )
A: |
B: |
C: |
D: |
- 提示1:PHA+QeaUueWPmOWKm+eahOaWueWQke+8jOS9huaYr+S4jeaUueWPmOWKm+eahOWkp+WwjzwvcD4=
- 提示2:PHA+QuaUueWPmOWKm+eahOWkp+Wwj++8jOS9huaYr+S4jeaUueWPmOaWueWQkTwvcD4=
- 提示3:PHA+ROaUueWPmOWKm+eahOWkp+Wwj++8jOS9huaYr+S4jeaUueWPmOWKm+eahOaWueWQkTwvcD4=
- 答案:Qw==
PGRpdj5B5piv5a6a5ruR6L2u77yM5Y+q5pS55Y+Y5Yqb55qE5pa55ZCR77yM5LiN5pS55Y+Y5Yqb55qE5aSn5bCP77ybQuaYr+WKqOa7kei9ru+8jOaUueWPmOWKm+eahOWkp+Wwj++8jOS9huaYr+S4jeaUueWPmOWKm+eahOaWueWQke+8m0PmmK/mu5Hova7nu4TvvIzmi4nlipvnmoTmlrnlkJHlkJHkuIvvvIzniankvZPov5DliqjlkJHkuIrvvJtE5piv5ruR6L2u57uE77yM5ouJ5Yqb5ZCR5LiK77yM54mp5L2T6L+Q5Yqo5ZCR5LiK44CCPGJyPjwvZGl2Pg==
本课配套习题挑战模式3/5
如图所示,表示用滑轮或滑轮组提起同一重物的几种方法,其中最省力的是(动滑轮重和摩擦忽略不计)()
A: |
B: |
C: |
D: |
- 提示1:PHA+5Yik5pat5pyJ5aSa5bCR6IKh57uz5a2Q5ouJ5Yqo5LiL6Z2i55qE5Yqo5ruR6L2uPC9wPg==
- 提示2:PHA+5Yik5pat5pa55rOV5pyJ5Lik56eN77yM5LiA56eN55qE5YiH5Ymy77yM5Y+m5LiA56eN5piv55yL5oyC6ZKp5piv5ZCm5pyJ57uz5a2QPC9wPg==
- 提示3:PHA+5Lqy77yB5YaN55yL5o+Q56S65bCx5piv562U5qGI5LqG44CC5p+l5pWw5oC76K+l5Lya5LqG5ZCn44CCPGJyPjwvcD4=
- 答案:Qw==
PGRpdj7lj6ropoHliKTmlq3lh7rmnInlpJrlsJHogqHnu7PlrZDmi4nnnYDliqjmu5Hova7ljbPlj6/vvIznu7PlrZDogqHmlbDotorlpJrotornnIHlipvjgII8YnI+PC9kaXY+
本课配套习题挑战模式4/5
某同学的最大拉力是250N,他想站在地上提起重900N的物体,下列哪种设计是正确的( )
A: |
B: |
C: |
D: |
- 提示1:PHA+5q2k6aKY5LiN5LuF6KaB6ICD6JmR5Y+X5Yqb5oOF5Ya177yM6L+Y6KaB6ICD6JmR5p+Q5ZCM5a2m56uZ5Zyo5Zyw6Z2i5LiK5ouJ54mp5L2T44CCPC9wPg==
- 提示2:PHA+55yL5pyJ5aSa5bCR6IKh57uz5a2Q5ouJ552A5Yqo5ruR6L2u77yM55So5ouJ5Yqb5LmY5Lul57uz5a2Q55qE6IKh5pWw5aSn5LqO54mp5L2T6YeN5Yqb5Y2z5Y+v44CCPC9wPg==
- 提示3:PHA+5pu0566A5Y2V55qE5pa55rOV5piv5om+5Ye657uz5a2Q6IKh5pWw5pyA5aSa55qE77yM54S25ZCO5ouJ5Yqb5pa55ZCR5ZCR5LiL5Y2z5piv5oiR5Lus6KaB55qE562U5qGI44CCPGJyPjwvcD4=
- 答案:RA==
PGRpdj7mib7lh7rnu7PlrZDmi4nlipvlkozniankvZPph43lipvnmoTlhbPns7vvvIzpgJrov4fmnIDlpKfmi4nlipvorqHnrpflh7rog73lpJ/mi4nliqjnmoTniankvZPmnIDlpKfph43lipvvvIzlkIzml7bopoHogIPomZHkurrnq5nlnKjlnLDpnaLmi4nvvIzmi4nlipvopoHlkJHkuIvvvIzlpoLmnpzmi4nlipvlkJHkuIrvvIzpgqPlj6rog73lnKjlnLDkuIrlhYjmjJbkuKrlnZHkuobvvIzkvZXlv4XlpJrmraTkuIDkuL7lkaLjgII8L2Rpdj4=
本课配套习题挑战模式5/5
一位同学双手的最大拉力为500N,现在他用一个动滑轮和一个定滑轮组成的滑轮组,若不计滑轮重和摩擦,最多能提起的物重为( )
A: 500N |
B: 1000N |
C: 1500N |
D: 250N |
- 提示1:56Gu5a6a5q2k5ruR6L2u57uE6IO95aSf5Lqn55Sf55qE57yg57uV5pa55byP
- 提示2:PHA+6KaB5oOz5pyA55yB5Yqb77yM5Yqo5ruR6L2u57yg57uV55qE57uz5a2Q6IKh5pWw5bqU6K+l5pyA5aSnPC9wPg==
- 提示3:PHA+5LiA5Liq5ruR6L2u6IO957yg57uV5Lik6IKh57uz5a2Q77yM5Yqg5LiK5oyC6ZKp5YaN5aKe5Yqg5LiA6IKh57uz5a2QPC9wPg==
- 答案:Qw==
PGRpdj7nvKDnu5XmlrnlvI/mnInkuKTnp43vvIzkuIDnp43mmK/liqjmu5Hova7mnInkuKTogqHnu7PlrZDvvIzkuIDnp43mmK/liqjmu5Hova7mnInkuInogqHnu7PlrZDvvIzmj5DotbfmnIDph43niankvZPvvIzmiYDku6Xph43nianlupTor6XmmK/mi4nlipvnmoTkuInlgI3jgII8YnI+PC9kaXY+