1/5单选题
难度：
1.
用动滑轮提升重物，物体重180N，动滑轮重20N，绳重和摩擦不计. 在竖直向上的拉力F的作用下，物体以0.1m/s的速度匀速上升，拉力及拉力做功的功率（ ）
| A | 100N,20W |
| B | 100N,10W |
| C | 200N,20W |
| D | 200N,10W |
- 提示1：
- PHA+5Yqo5ruR6L2u5Y+v5Lul55yB5LiA5Y2K55qE5YqbPC9wPg==
- 提示2：
- PHA+57uz5a2Q56e75Yqo55qE6YCf5bqm5piv54mp5L2T6YCf5bqm55qE5LqM5YCN44CCPC9wPg==
- 提示3：
- PHA+5Yip55So5YWs5byPUD1GduaxgjwvcD4=
正确答案：QQ==
PGRpdj7op6PvvJoyRj1HK0c8c3ViPkQ8L3N1Yj7vvIzmiYDku6VGPTEwME7vvIxQPUZ2PTEwME7DlzLDlzAuMW0vcz0yMFcuPC9kaXY+
2/5单选题
难度：
2.
如图所示，是使用汽车打捞水下重物示意图，在重物从水底到井口的过程中，汽车以恒定的功率向右运动，忽略水的阻力和滑轮的摩擦，四位同学画出了汽车速度随时间变化的图象，其中正确的是（ ）
| A |
|
| B |
|
| C |
|
| D |
|
- 提示1：
- PHA+5LiA5byA5aeL5ouJ5Yqb5bCP5LqO5Ye65rC05ZCO55qE5ouJ5YqbPGJyPjwvcD4=
- 提示2：
- PHA+6YCf5bqm5ouJ5Yqb5aKe5aSn77yM6YCf5bqm5YeP5bCPPGJyPjwvcD4=
- 提示3：
- PHA+5qC55o2uUD1GduWIhuaekDxicj48L3A+
正确答案：RA==
PGRpdj7op6PvvJrkuIDlvIDlp4vmi4nlipvlsI/kuo7lh7rmsLTlkI7nmoTmi4nlipvvvIwg5ouJ5Yqb5aKe5aSn77yM6YCf5bqm5YeP5bCP77yM5YmN5ZCO6YO95YGa5YyA6YCf55u057q/6L+Q5Yqo77yM5Lit6Ze05aSE5LqO5YeP6YCf54q25oCB77yM5omA5Lul6YCJROOAgjwvZGl2Pg==
3/5单选题
难度：
3.
如图所示，体积为800cm3的泡沫块在拉力F的作用下恰好浸没在水中，若ρ泡沫=0.2×103kg/ m3，绳与轮之间摩擦、水的阻力不计，20s内将该泡沫块拉到水面下8m深处，拉力F的功率为（ ）（g=10N/kg）
| A | 29.6W |
| B | 14.8W |
| C | 2.56W |
| D | 1.48W |
- 提示1：
- PHA+5YWI5rGC5Ye65rOh5rKr55qE6YeN5Yqb5ZKM5rWu5YqbPGJyPjwvcD4=
- 提示2：
- PHA+5rGC5Ye657uz5a2Q55qE5ouJ5YqbPC9wPg==
- 提示3：
- PHA+5Yip55So5Yqf546H55qE5YWs5byP5rGC5Yqf546HPC9wPg==
正确答案：Qw==
PGRpdj7op6PvvJpHPc+BPHN1Yj7ms6Hmsqs8L3N1Yj5nVj0xLjZOLCBGPHN1Yj7mta48L3N1Yj49z4E8c3ViPuawtDwvc3ViPmdWPThOLCDmiYDku6VGPTYuNE4sIDxicj48L2Rpdj48ZGl2PnY9OG0vMjBzPTAuNG0vcyw8YnI+PC9kaXY+PGRpdj5QPUZ2PTYuNE7DlzAuNG0vcz0yLjU2V+OAgjxicj48L2Rpdj4=
4/5单选题
难度：
4.
用如图所示装置将质量为89kg的铜块在10s内在水中匀速提升2m，若已知动滑轮重50N，不计水的阻力和摩擦。（ρ铜=8.9×103kg/ m3，g=10N/kg），拉力F的功率为（ ）
| A | 89W |
| B | 168W |
| C | 150W |
| D | 158W |
- 提示1：
- PHA+5YWI5rGC5Ye66YCf5bqm44CB6ZOc5Z2X55qE6YeN5Yqb5ZKM5omA5Y+X5rWu5YqbPC9wPg==
- 提示2：
- PHA+5rGC5Ye65ouJ5YqbPC9wPg==
- 提示3：
- PHA+5Yip55SoUD1GduaxguWHuuWKn+eOhzxicj48L3A+
正确答案：Qg==
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
5/5单选题
难度：
5.
如图，在水平拉力F作用下，5秒内使重40N的物体A匀速移动5m，物体A受到地面的摩擦力为5N，不计滑轮、绳子的重力及滑轮与绳子间的摩擦，拉力F做的功和功率分别为（）
| A | 50J，10W |
| B | 25J，10W |
| C | 100J 25W |
| D | 25J，5W |
- 提示1：
- PHA+6L+Z5piv5LiA5Liq6LS55Yqb55qE6KOF572u77yM55yB6Led56a7PC9wPg==
- 提示2：
- PHA+5ouJ5Yqb5bqU5Li6MTBOPC9wPg==
- 提示3：
- PHA+5ouJ5Yqb55qE6YCf5bqm5Li6MC41bS9zPC9wPg==
正确答案：RA==
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