(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Luke stands on a scale in an elevator which has a constant acceleration upward. The scale reads 0.97 kN. When Luke picks up a box of mass 20 kg, the scale reads 1.18 kN. (The acceleration remains the same.) (a) Find the acceleration of the elevator. (b) Find Luke's weight.

2. Relevant equations

So I came up with 2 equations one for Luke w/o the added mass one for Luke with.

W_1 = m(g+a) I solve it for m.

m = W_1 / (a+g)

equation 2

W-2-(m+20)g=(m+20)a

3. The attempt at a solution

My strategy is to just solve both equation for m. Set them equal and then just plug and chug and get my my a. The issue is I can't solve the equation!!!!!!!

If my strategy is correct. The units don't work out at all. Apples and Oranges.

So,

W_2 - 20g - 20a / a+g =W_1/ a+g

Multiply both sides by a+g gave

W_2 - 20g -20a = W_1

Cleaning it up for a I got...

W_2 -20g - W_1 / 20 = a

See what I meant about apples and oranges something is wrong. I have been at it for a while I have tunnel vision.

Thanks to whoever helps

**Physics Forums - The Fusion of Science and Community**

# Solving simultaneous equations F = ma

Know someone interested in this topic? Share a link to this question via email,
Google+,
Twitter, or
Facebook

- Similar discussions for: Solving simultaneous equations F = ma

Loading...

**Physics Forums - The Fusion of Science and Community**