What is the magnitude of the elevators acceleration

In summary: Fnet=Mg-W(apparent).......4substituting equation 3 in equation 4Ma=Mg-W(apparent)a=(g-W(apparent)/Ma=(9.8-140)/72.6a= -1.8m/s^2In summary, the magnitude of the elevator's acceleration is -1.8 m/s^2.
  • #1
catmd13
9
0

Homework Statement



When you weigh yourself on good old terra firma (solid ground), your weight is 160lb . In an elevator your apparent weight is 140lb. What is the magnitude of the elevators acceleration.

Homework Equations



For this problem would we use the equation Fn= mg+ma

The Attempt at a Solution

 
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  • #2
catmd13 said:

Homework Statement



When you weigh yourself on good old terra firma (solid ground), your weight is 160lb . In an elevator your apparent weight is 140lb. What is the magnitude of the elevators acceleration.

Homework Equations



For this problem would we use the equation Fn= mg+ma

The Attempt at a Solution


Welcome to PF.

That equation is ok.

Be careful what you use for g since your givens are in lbs.
 
  • #3
i used the equation listed above but i get keep getting a wrong answer.

i used 160lb for Fn and 123 for mg i not really sure what to use for ma. I was also wondering if I should change the units from pounds
 
  • #4
ma = -mg + Fn
 
  • #5
they gave you mg and Fn, Fn is your apparent weight. mg is normal weight
 
  • #6
so they give me Fn= 63.5kg and mg= 72.6kg i plugged it into find ma and i came up with .123 and it is still wrong. Can you help me out and see where i am making my mistake
 
  • #7
catmd13 said:
so they give me Fn= 63.5kg and mg= 72.6kg

Note that Fn is a force, while "63.5 kg" is a mass. So they cannot be equal.

Did you use selter01's equation,

ma = -mg + Fn​

?

m=72.6 kg, and you're trying to find "a".
 
  • #8
I used that equation how would i express 63.5kg as a force so i could use it for Fn I am stuck and do not know where to go from here
 
  • #10
as we know that the equation relating the Apparent and the Real weight is given as
Fnet=W(real)-W(apparent)...1

but
W(real)=Mg....... ...2
and F(net)=Ma........ ...3
 

1. What does magnitude of acceleration refer to?

The magnitude of acceleration refers to the measurement of how much an object's velocity changes over time. It is usually measured in meters per second squared (m/s²) in the metric system or feet per second squared (ft/s²) in the imperial system.

2. How is the magnitude of acceleration calculated?

The magnitude of acceleration can be calculated by dividing the change in velocity (final velocity - initial velocity) by the change in time. This is represented by the formula: a = (vf - vi) / t, where "a" is acceleration, "vf" is final velocity, "vi" is initial velocity, and "t" is time.

3. What factors affect the magnitude of acceleration?

The magnitude of acceleration can be affected by various factors such as the force applied to the object, the mass of the object, and any resistance or friction present. The direction of the acceleration also plays a role as it can either increase or decrease the overall magnitude.

4. How is magnitude of acceleration different from velocity?

Velocity refers to the speed and direction of an object's motion, while magnitude of acceleration refers to the rate of change of an object's velocity. In other words, velocity tells us the object's current state of motion, while magnitude of acceleration tells us how much that motion is changing.

5. Why is it important to measure the magnitude of acceleration?

Measuring the magnitude of acceleration is important in understanding an object's motion and how it changes over time. It is also crucial in engineering and designing systems that involve motion, such as elevators, cars, or planes, as it allows for the calculation of necessary forces and adjustments to ensure safe and efficient movement.

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