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For qn5, the person weight 400N, when release the person, the string experience 500N, the line we draw shouldn't be longer than 7cm?

pika93

12d) gravitational potential energy can??

Anu

Question 5.My answer was 857N because i multiple 12 cm with (500/7)....is it possible to get marks for it??

冷风1985

tianya1 发表于 2-11-2011 19:10
12 a
the force exerts by foot should be greater than the piston since it has a shorter perpendicular ...

No.
The perpendicular distance from the pivot to the force exerted by foot is longer than the other.

冷风1985

kyukyung 发表于 2-11-2011 20:46
same! i also said it will move backwards, away from the lens

Yes, you are correct.

冷风1985

pika93 发表于 2-11-2011 23:52
12d) gravitational potential energy can??

Sorry, your answer cannot be accepted.
The question never mensions the car is moving up a slop.

Anu

Question 5.My answer was 857N because i multiple 12 cm with (500 / 7 ).... is it possible to get marks for it??

冷风1985

Anu 发表于 8-11-2011 11:08
Question 5.My answer was 857N because i multiple 12 cm with (500 / 7 ).... is it possible to get mar ...

No worries, that will most probably be accepted, since there is only a difference of 1mm.