- #1
Ralph777
- 8
- 0
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.
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
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
Homework 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
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