How to Calculate Net Force on Elevator Moving Downward with Upward Acceleration?

In summary, the conversation discusses finding the net force of an elevator that weighs 600 N and is accelerating downward at 2.0 m/s/s while also accelerating upward at 9.8 m/s/s. The attempted solution involves using the equations F=ma and w=mg to calculate the net force, resulting in a value of 722.4 N. There is some confusion about the direction of acceleration and the resulting change in weight on the scale.
  • #1
bling-bling
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0

Homework Statement


A weighs 600 N on an elevator when it is stationary. Each elevator accelerates according to the specified arrow that is drawn next to it. In all cases where the elevator is moving, it is moving downward.
Find net force, if the elevator is accelerating 2.0 m/s/s upward, even though the elevator is moving downward. Use g = 9.8 m/s/s


Homework Equations


w = mg
F = ma


The Attempt at a Solution


Well this is what i did: F = ma
Fn - mg = ma
Fn = ma + mg
Fn = 61.2(2) + 61.2(9.8)
Fn = 722.4 N
Is that right?
 
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  • #2
That question seems contradictory. It's accelerating upward, even though it's moving downward? That isn't what Newton's Laws state.
 
  • #3
well the elevator is moving downward, and if the accleration is upward, doesn't that mean that the elevator is slowing down?
 
  • #4
My apologies, you're right. I haven't worked dynamics in a while. Regardless, your work looks good.
 
  • #5
So our scale weight is increasing as we're going down? Shouldnt it be decreasing? Because my teacher said, that the formula should be Fn = ma + -mg
 

Related to How to Calculate Net Force on Elevator Moving Downward with Upward Acceleration?

1. How do I calibrate my scale for accurate weight measurement?

To calibrate your scale, place a known weight (such as a dumbbell or bag of flour) on the scale and adjust the reading to match the weight. Repeat this process at least two more times with different weights to ensure accuracy.

2. How do I properly step on a scale to get an accurate weight?

It is important to stand as still as possible when weighing yourself. Step onto the scale with your feet evenly placed and distribute your weight equally. Avoid leaning on the walls or holding onto anything for balance.

3. Why does my scale show different weights at different times of the day?

Weight can fluctuate throughout the day due to factors such as hydration levels, food consumption, and activity levels. It is best to weigh yourself at the same time each day to get a more accurate measurement.

4. What is the most accurate way to track weight loss or gain?

Using the same scale consistently is the best way to track weight loss or gain. It is also important to weigh yourself at the same time, on the same day of the week, and in similar conditions (such as before breakfast). This will provide more consistent and accurate results.

5. How do I interpret my weight measurement on a scale?

Weight is measured in pounds or kilograms on most scales. It is important to remember that weight is just one aspect of overall health and can fluctuate for various reasons. It is best to focus on overall health and wellness rather than just a number on the scale.

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