Stationary elevator homework problem

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To solve the stationary elevator problem, consider Allison's apparent weight when accelerating upwards at 8 m/s². The scale measures the upward force on her, which can be calculated using Newton's 2nd law. By adding the acceleration to the standard gravitational force of 9.8 m/s², the effective gravitational force becomes 17.8 m/s². Consequently, Allison's apparent weight is her mass multiplied by this new gravitational force. Understanding these concepts clarifies how acceleration affects perceived weight in a stationary elevator scenario.
ryan1357
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I'm doing this Physics worksheet and I don't know how to do this problem...
Allison is standing on a scale that is in a stationary elevator. what is the apparent weight when she is moving up at 8 m/s squared?

If anyone can help that would be great.. And if you could explain the steps you used to get it.

Thanks
 
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The scale reads the force that pushes up on the girl. Draw a diagram showing the forces on the girl (there are two). The net force on the girl is related to her acceleration by Newton's 2nd law. (Hint: you can express the girl's apparent weight in terms of her actual weight.)
 
Just think of the acceleration upwards as more gravity.

The "gravity" has increased from 9.8 to 17.8 m/s^2.

Therefore her apparent weight is just her mass times the new "gravity".
 
Thread 'Variable mass system : water sprayed into a moving container'

Thread 'Variable mass system : water sprayed into a moving container'

Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
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