University of Colorado Friction Forces Lab Report

User Generated

oqoqvd

Science

university of colorado

Description


Unformatted Attachment Preview

Lab 4 – Friction Forces Name: ____________________________________________________ Objectives 1. To understand the effect of the forces of friction during the motion of objects. 2. To explore experimentally the Newton’s Second Law (relation between force, mass and acceleration) In your responses use scientific terms such as, constant, increase, decrease, velocity, force, mass and acceleration. Click on the link below to open the simulation: http://phet.colorado.edu/en/simulation/ramp-forces-and-motion . You will be starting with a crate that has a mass of 100 kg and a coefficient of sliding friction of 0.3 and a coefficient of static friction of 0.5. 1. Draw the Free Body Diagram before you apply any force. 2. Add 10 N of applied force, and push the button and record what happens. Include a free body diagram showing all the forces. 3. Add 100 N of applied force and push the button. What changed? 4. Use the friction equation to calculate how much force would be required to get it moving. Show your work here. What happened? How did you fix the problem to get it moving? 5. What happened as the crate moved up the ramp? Show the free body diagram while the crate is on the ramp. What force is working against your applied force? 6. Reset all. Predict what you think would happen if you increased the angle. What actually happened? Explain why you saw what you saw. 7. Reset all. Predict what you think would happen if you decreased the angle. Try it out. Why? 8. Place the crate on the ramp with the angle at 20o. What is true about the parallel force and the friction force if the crate does not go down the ramp? Slowly increase the angle until the block JUST starts to move. Use the angle to calculate μs and compare to the given value for μs for the crate. 9. Calculate how much force you would have to apply to the crate to get it to go at constant speed up the 30o ramp. Show your work below and record your answer to the tenth of a Newton (Hint: Remember it’s moving now, so which μ do you need to use?) 10. Go to the “Forces Graph” tab. Reset all. Input your applied force and push play. Stop the crate before it crashes into the wall. Is your net force = 0? What does that tell you about the motion of the crate? 11. Place the block at the top of the 30o ramp (Position = 8.9 m). What is the net force on the block down the ramp? (Show your calculation below). What is the acceleration of the block down the ramp? (Include in your calculation). What would be the final velocity of the block at the bottom of the ramp? 12. What force is acting on the crate once it hits the flat part at the bottom of the ramp? What is the magnitude and direction of that force? 13. What will be the acceleration of the crate on the flat part at the bottom of the ramp? 14. Calculate how far the crate should slide at the bottom. Try it out. How did your calculation compare to the applet result? 15. Change your object to the “Mystery Object” and reduce your angle. Using what you learned above, calculate the mass, μs and μk for the Mystery Object. Show all your measurements and your work. Be careful to state whether your measurement is on the ramp or on the flat part. (Hint: Start by finding μs first with the ramp raising). You may need to reset all occasionally. Flat Part Calculations/Measurements Ramp Calculations/Measurements
Purchase answer to see full attachment
User generated content is uploaded by users for the purposes of learning and should be used following Studypool's honor code & terms of service.

Explanation & Answer

Attached.

Lab 4 – Friction Forces
Name: ____________________________________________________
Objectives
1. To understand the effect of the forces of friction during the motion of objects.
2. To explore experimentally the Newton’s Second Law (relation between force, mass and
acceleration)
In your responses use scientific terms such as, constant, increase, decrease, velocity, force, mass
and acceleration.
Click on the link below to open the simulation:
http://phet.colorado.edu/en/simulation/ramp-forces-and-motion
.

You will be starting with a crate that has a mass of 100 kg and a coefficient of sliding friction of
0.3 and a coefficient of static friction of 0.5.

1. Draw the Free Body Diagram before you apply any force.
Normal force

WWeight (100g)
2. Add 10 N of applied force, and push the
free body diagram showing all the forces.

button and record what happens. Include a

No motion.
Fn
Applied force
Friction force
Fg

3. Add 100 N of applied force and push the

button. What changed?

No motion again. But the friction force was increased as increase of the applied force.
4. Use the friction equation to calculate how much force would be required to get it moving.
Show your work here. What happened? How did you fix the problem to get it moving?
Applying 𝐅 = 𝛍𝐑
𝐅 = 𝟎. 𝟓(𝟏𝟎𝟎𝐠) = 𝟎. 𝟓(𝟏𝟎𝟎)(𝟗. 𝟖) = 𝟒𝟗𝟎 𝐍
After applying 490N, no motion. The reason for that is the friction force still equal to the
applied force. To move the mass the applied force should be larger than this force.
Therefore, the problem was solved by increasing the applied force little than 490N.

5. What happened as the crate moved up the ram...


Anonymous
I was stuck on this subject and a friend recommended Studypool. I'm so glad I checked it out!

Studypool
4.7
Trustpilot
4.5
Sitejabber
4.4

Similar Content

Related Tags