This is not an actual problem from my class. All our problems involved an elevator going upward (both accelerating and decelerating). But I am curious if an elevator cable would have the same FT if the elevator was decelerating downward at -3 m/s2 as it would accelerating upward at 3 m/s2 ? I am having a hard time conceptualizing why that is true in my mind's eye.(adsbygoogle = window.adsbygoogle || []).push({});

2. Relevant equations

Elevator Up: FT - mg = ma

so: FT = m (a + g)

so I figure that:

@ a<0 FT< FG

@ a=0 FT= FG

@ a>0 FT > 0

I was curious what the values are when the elevator is going down.

I used this equation: mg - FT = ma

so: FT = m ( g - a )

so I figure that:

@ a<0 FT> FG

@ a=0 FT= FG

@ a>0 FT< FG

3. The attempt at a solution

Is it true that an elevator cable would have the same FT if the elevator was decelerating downward at -3 m/s2 as it would accelerating upward at 3 m/s2 ? I am having a hard time conceptualizing why that is true in my mind's eye.

Thanks

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Elevator decelerating down vs accelerating up

**Physics Forums | Science Articles, Homework Help, Discussion**