Calculating starting/tractive force

  • Thread starter Thread starter snwright
  • Start date Start date
  • Tags Tags
    Force
AI Thread Summary
To calculate the force needed to overcome inertia for a 1500 lb sliding door, the initial calculation of 93.74 lbs is based on acceleration without considering friction. To include friction, the resistance force is determined by multiplying the weight of the door by the coefficient of friction, which requires adjusting for the four wheels to ensure even load distribution. The correct formula incorporates both friction and acceleration: F = m(0.02g + a), where g is 9.81 m/s² and m is the mass in kg. After calculations, the total force required amounts to 176 N or approximately 40 lbs. Understanding these dynamics is crucial for accurate force calculations in similar applications.
snwright
Messages
5
Reaction score
0
Hey all-

First post here!

I need to calculate the force required to overcome inertia of a 1500lb object. It's a sliding door, which rolls on 4 identical wheels, each with a coefficient of friction of .02. I'd like to make it accelerate to .25m/s over a period of 4 seconds.

I think what I need OMITTING FRICTION is: F=Ma = 6672 N * .0625m/s2 = 417 N = 93.74 lbs. Is that accurate? How do I include the resistance due to friction?

thanks!

Spencer
 
Engineering news on Phys.org
Resistance due to friction is weight of door times coefficient of friction. You need that much additional force. Be careful about how you consider the four wheels.
 
How should I be considering them? The load should be distributed pretty evenly across all four wheels. I was thinking that it would be a wash, and that the accumulated drag would be .02.
 
You need to add all the resistance forces to the inertia. The force needed would be:

F = 0.02mg + ma = m (0.02g + a)

g is 9.81 m/s² and the SI unit for m is kg not N (So 1500 lb is 680 kg). F = 176 N = 40 lb.
 

Thread 'Bubble formation in 4 mm gap vessel'

How did you find PF?: Via Google search Hi, I have a vessel I 3D printed to investigate single bubble rise. The vessel has a 4 mm gap separated by acrylic panels. This is essentially my viewing chamber where I can record the bubble motion. The vessel is open to atmosphere. The bubble generation mechanism is composed of a syringe pump and glass capillary tube (Internal Diameter of 0.45 mm). I connect a 1/4” air line hose from the syringe to the capillary The bubble is formed at the tip...
View full post »
Thread 'Physics of Stretch: What pressure does a band apply on a cylinder?'

Thread 'Physics of Stretch: What pressure does a band apply on a cylinder?'

Scenario 1 (figure 1) A continuous loop of elastic material is stretched around two metal bars. The top bar is attached to a load cell that reads force. The lower bar can be moved downwards to stretch the elastic material. The lower bar is moved downwards until the two bars are 1190mm apart, stretching the elastic material. The bars are 5mm thick, so the total internal loop length is 1200mm (1190mm + 5mm + 5mm). At this level of stretch, the load cell reads 45N tensile force. Key numbers...
View full post »

Thread 'Find 3D Printer & Software Resources for Prototype Creation'

I'd like to create a thread with links to 3-D Printer resources, including printers and software package suggestions. My motivations are selfish, as I have a 3-D printed project that I'm working on, and I'd like to buy a simple printer and use low cost software to make the first prototype. There are some previous threads about 3-D printing like this: https://www.physicsforums.com/threads/are-3d-printers-easy-to-use-yet.917489/ but none that address the overall topic (unless I've missed...
View full post »

Similar threads

Calculating Tractive Effort on a Slope: A Case Study
Replies
2
Views
2K
Help Walk Me Thru Motor Sizing Calculations Please
Replies
14
Views
2K
Automotive Need help calculating load torque and acceleration torque of a vehicle
Replies
8
Views
6K
Automotive How to calculate hydraulic disc brake size using actuation force?
Replies
15
Views
6K
What is the Best Method for Calculating Rolling Resistance in Train Carriage?
Replies
5
Views
5K
Automotive How do I calculate required torque for two dc motors?
Replies
3
Views
2K
Calculating the forces on a crankshaft assembly
Replies
9
Views
5K
Torque calculations: Rotating vertical shaft
Replies
5
Views
5K
Torque needed to start rolling motion on a inclined surface
Replies
10
Views
7K
Maximum weight carried by a specific torque
Replies
6
Views
3K

Hot Threads

Recent Insights

Back
Top