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a 95.0 kg person stands on a scale in an elevator. what is the apparent weight when the elevator is accelerating upward with an acceleration os 1.80 m/s^2?
I dont want the answer just some direction, i have tried a few different methods and none of them work out.

2007-11-06 07:13:59 · 2 answers · asked by Anonymous in Science & Mathematics Physics

2 answers

Let
Wa be apparent Weight
g- acceleration due to gravity
a - acceleration of the elevator
Then

Upward
Wa=m(g+a)

Downward
Wa=m(g-a)

2007-11-06 07:44:19 · answer #1 · answered by Edward 7 · 0 0

If the elevator accelerating upward then we have force of inertia directed downward. Then, Resulting force is a sum of original weight and additional force.

F = Weight + Inertia
F = m x g + m x 1.80 = m x ( 9.81 + 1.80 ) = 95 x 11.61 =

1103 N

Regularly, out of elevator, 95 Kg person has a force: m x g = 95 x 9.81 = 932 N

Your mass is the same in kg, but force that your body push the ground is greater. If you want to calculate how much is your effective weight greater in kg, than you just have to calculate percent of your acceleration increase.
Thus:
11.61/9.81 = 1.18 times greater

In practice, scale will be also forced by own inertia, so you need to subtract that additional force if you want correct result.

2007-11-06 16:03:19 · answer #2 · answered by ervetor 1 · 0 0

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