What Is the Elevator's Z Acceleration When Your Apparent Weight Is Half?

Thread starter gtaylor
Start date Aug 18, 2009
Tags

Acceleration

AI Thread Summary

When standing on a scale in an elevator, an apparent weight that is half of the real weight indicates that the elevator is accelerating downwards. The relationship between apparent weight and acceleration can be expressed using Newton's Second Law, where the net force equals mass times acceleration. In this scenario, the z acceleration (az) of the elevator can be calculated as az = -0.5g, where g is the acceleration due to gravity. This negative sign indicates that the acceleration is directed downward. Understanding this concept is crucial for analyzing forces in non-inertial reference frames.

Aug 18, 2009

gtaylor

Imagine that you are standing on a scale in an elevator and you find that your apparent weight as read by the scale is half your real weight. What is the elevator's z acceleration az relative to the ground? Express you answer as a multiple of g, and make sure that your value for az has the correct sign.

Physics news on Phys.org

Aug 18, 2009

kuruman

Science Advisor

Homework Helper

Education Advisor

Insights Author

Gold Member

Draw a free body diagram and write down Newton's Second Law. Go for it.

Thread 'I've come across another fluid pressure problem I don't understand'

Neglect gravity other than that of water; neglect friction. F1=ρgsh=1000*10*1*(1+4)=50000 N; F1=ρgsh=1000*10*0.1*4=4000 N; F3=50000-4000=46000 N?

View full post »

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}...

View full post »

Thread 'Egg Drop Challenge! Need ideas for winning designs'

I was thinking using 2 purple mattress samples, and taping them together, I do want other ideas though, the main guidelines are; Must have a volume LESS than 1600 cubic centimeters, and CAN'T exceed 25 cm in ANY direction. Must be LESS than 1 kg. NO parachutes. NO glue or Tape can touch the egg. MUST be able to take egg out in less than 1 minute. Grade A large eggs will be used.

View full post »