Newton's second law

向上加速=向下減速
you will feel HEAVIER (較重)

Because by looking at acceleration, upward Force > downward Force
Normal reaction> Weight,
you will feel heavier.


向上減速=向下加速
you will feel LIGHTER (較輕)
By looking at acceleration, upward Force < downward Force
Normal reaction < Weight,
you will feel lighter.

首先~我地要清楚知道有咩力作用係整個個程中.
1:R 由地下施係我地身上既反作用力
2:mg 我地既重量 (m)係我地既mass (g)係gravity 一般當係10
設我地既重量係60kg~當我地站在靜止既lift~
R=mg
=60*10
=600N

向上加速度~設加速度(a)係1.5ms-2
lift 向上加速時~ (R比mg大)
根據 F=ma
R-mg=ma
R=m(g+a)
=60*(10+1.5)
=690N
在呢個過程~我地會覺得體重上升

向上減速度...部lift向上個陣~個R一定大過mg
R-mg=ma
R=m(g+a)
所以向上個陣一定係加速度黎~
你只可以話上得慢d~但仲係加速黎~
在呢個過程~我地會覺得體重上升~只不過體重上升較小

向下減速度
設減速度(a)係1.5ms-2
lift 向下減速時 ~(mg比R大 )
根據 F=ma
mg-R=ma
R=m(g-a)
=60*(10-1.5)
=510N
在呢個過程~我地會覺得體重下降