New User Special Price Expires in

Let's log you in.

Sign in with Facebook


Don't have a StudySoup account? Create one here!


Create a StudySoup account

Be part of our community, it's free to join!

Sign up with Facebook


Create your account
By creating an account you agree to StudySoup's terms and conditions and privacy policy

Already have a StudySoup account? Login here

Physics Online Notes from Readings 9/27 and 10/2

by: Kiersten Notetaker

Physics Online Notes from Readings 9/27 and 10/2 PHYS 23300 - 001

Marketplace > Purdue University > PHYS 23300 - 001 > Physics Online Notes from Readings 9 27 and 10 2
Kiersten Notetaker
View Full Document for 0 Karma

View Full Document


Unlock These Notes for FREE

Enter your email below and we will instantly email you these Notes for Physics For Life Sciences I

(Limited time offer)

Unlock Notes

Already have a StudySoup account? Login here

Unlock FREE Class Notes

Enter your email below to receive Physics For Life Sciences I notes

Everyone needs better class notes. Enter your email and we will send you notes for this class for free.

Unlock FREE notes

About this Document

These notes cover what readings were assigned this week. These are the topics most likely on this week's quiz (Monday, 10/3)
Physics For Life Sciences I
Stephen M Durbin
Class Notes




Popular in Physics For Life Sciences I

Popular in Department

This 4 page Class Notes was uploaded by Kiersten Notetaker on Sunday October 2, 2016. The Class Notes belongs to PHYS 23300 - 001 at Purdue University taught by Stephen M Durbin in Fall 2016. Since its upload, it has received 9 views.


Reviews for Physics Online Notes from Readings 9/27 and 10/2


Report this Material


What is Karma?


Karma is the currency of StudySoup.

You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!

Date Created: 10/02/16
Physics 233 online notes based on readings from 9/27 and 10/2 Viscosity - Interaction of molecules in a fluid results in an internal friction that works to slow down the motion of neighboring layers of fluid. For example: Plate Keep the bottom plate at rest, and moving the top plate in the direction of the arrow with a constant velocity. Fluid Fluid is being pulled so that the amount Plate Not of deformation of the fluid changes moving perpendicular to the direction of the - At the top of the plate, the fluid moves with the plate - Some of the fluid at the bottom of the not moving plate will remain at rest - This sets up a gradient of velocity Rate of change with respect to space -The layers of fluid move past each other as shown - Those at the top of the fluid (near the top plate being actively moved) have the greatest velocity -Those at the bottom of the fluid (near the bottom plate held at rest) have the lowest velocity Equation (still using example above) - Both plates have an area (A) - Both separated by a thickness (Y) - We’re holding the bottom plate and moving the top with a constant velocity (u) Acceleration of the plate is determined by Newton’s 2 ndLaw: net appiscous M *p =F p p = F p + F fluid->p *Note* if there were no internal resistance, any force on top would continue to app speed up. If we apply F on the plate it will speed up but its velocity will increase more slowly until it reaches constant velocity. - when the plate reaches a steady speed, acceleration is zero. - this shows that the force we’re applying is equal and opposite to the viscous force. F is: viscous Proportional to the speed of the plate Proportional to the area of the plate Inversely proportional to the distance between the moving plate and the fixed plate - We use μ to represent viscosity of fluid Viscosity of fluid= u= μ*( ) Ax y F= force y A= area μ= viscosity of fluid u= constant velocity y= thickness - Dimensionality of viscosity= M o Has SI system uniLT kg/m-s o We use force a lot with this so we rearrange and incorporate Newtons:  (N/m )*s - We also know about viscous forces on a sphere with radius (R) moving in a fluid: o Ffluid->sphere= -6piμRv viscous  R= radius, v=velocity DRAG - When an object moves through a fluid it feels resistance to its motion: o The object is dragging the fluid with it and making the fluid slide along itself. The fluid shows viscosity. o It’s pushing the fluid in front of it, making the fluid in front go with the same speed as the object.  This is called drag - The object exerts a force on the liquid in the direction of motion and the liquid pushes back in the opposite direction The cylinder will move Δx=vΔt Cylinder will sweep out all the molecules in a thin volume equal to the area of the circle*Δx V 2 2 -so Δv=piR Δx R Mass of molecules in this volume= the volume*density Δm = ρΔV Density Force equations for drag: F inertial=p∗g (pi∗R 2)v2 fluid →cylinder F ❑ =Ppi R v2 2 cylinder→ fluid So, The drag force that a fluid exerts on an object moving through it: - Opposes the motion - Is proportional to the density of fluid - Is proportional to the area being pushed through the fluid - Is proportional to the square of velocity of the object through the fluid Cdragis the drag coefficient - It’s determined by measurement but it’s usually close to 1 - USE THIS EQUATION FOR DRAG: inertialdrag 2 2 F fluid →cylindedragP (pi∗R v 2 Gravity - Weight is a force that can change an object’s velocity - We assume that the gravitational force on an object points down and is independent of position o This is referred to as flat earth gravity Flat Earth Gravity - Estimation excluding fast velocities, change in height, and change in position. - Ex: o Think of holding a ball and nothing is moving N N The F hand →ball ball →hand Object’s weight pushing down=upward normal force of the hand - Think of a large and small ball being dropped at the same time. They will hit the ground at the same time even though their masses are different. o The net force on an object is shared over the whole object - W E→A/m A constant independent of the object o (weight of the object divided by its mass= a constant independent of the object) - Constant independent of the object=g ❑ W E→ Am gA <- gravitational force equation W= weight E=earth m=mass - We mentioned above how weight is a force o The weight of an object is proportional to its mass o The constant g refers to gravitational field and is represented as 9.81N/kg Free Fall in Flat Earth Gravity - Gravitational force= weight - If the only force acting on an object is gravity we say it’s in free fall o Still has an initial velocity o Can be moving up or sideways and still be considered in free fall - We refer to free fall motion as projectile motion Δ x V x Shows that x motion had no acceleration so object Δt remains at whateer x-velocity it had when it was released V = Δ y y Δt y motion has a constant downward acceleration meaning y velocity is continuously changing ax=0 for x motion, average v= instantaneous (constant) velocity a =−g (vi+v f y for y mtion, average v= 2 Gravitational field o Gravitational force on an object of mass placed at that point is m*g, and the force vector points in the direction of that field vector - Force of gravity is proportional to the objects mass - The further we are from the center of the earth the weaker gravity is - The direction of the field is not the direction an object moves when it’s experiencing the forces of that field - The gravitational field doesn’t refer to the region of space where the gravitational force is significant o It refers to the set of vectors at each point in space - The gravitational field determines the gravitational force but the net force determines the acceleration - If an object is not moving and there are no other forces on it then it will accelerate in the direction of the arrow o If there are any other forces acting on it, it won’t accelerate in the direction of the arrow - Net force determines acceleration (Δv) o So, if the object already has a velocity, then the force of the arrow will point in the direction of the change in velocity not direction of velocity - If the ball is thrown in the direction Gravitation of the arrow, the field will push it al field down , but the direction of the motion of the ball won’t be in the direction of the field (The ball isn’t going to change its direction to move straight down like


Buy Material

Are you sure you want to buy this material for

0 Karma

Buy Material

BOOM! Enjoy Your Free Notes!

We've added these Notes to your profile, click here to view them now.


You're already Subscribed!

Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'

Why people love StudySoup

Jim McGreen Ohio University

"Knowing I can count on the Elite Notetaker in my class allows me to focus on what the professor is saying instead of just scribbling notes the whole time and falling behind."

Janice Dongeun University of Washington

"I used the money I made selling my notes & study guides to pay for spring break in Olympia, Washington...which was Sweet!"

Steve Martinelli UC Los Angeles

"There's no way I would have passed my Organic Chemistry class this semester without the notes and study guides I got from StudySoup."

Parker Thompson 500 Startups

"It's a great way for students to improve their educational experience and it seemed like a product that everybody wants, so all the people participating are winning."

Become an Elite Notetaker and start selling your notes online!

Refund Policy


All subscriptions to StudySoup are paid in full at the time of subscribing. To change your credit card information or to cancel your subscription, go to "Edit Settings". All credit card information will be available there. If you should decide to cancel your subscription, it will continue to be valid until the next payment period, as all payments for the current period were made in advance. For special circumstances, please email


StudySoup has more than 1 million course-specific study resources to help students study smarter. If you’re having trouble finding what you’re looking for, our customer support team can help you find what you need! Feel free to contact them here:

Recurring Subscriptions: If you have canceled your recurring subscription on the day of renewal and have not downloaded any documents, you may request a refund by submitting an email to

Satisfaction Guarantee: If you’re not satisfied with your subscription, you can contact us for further help. Contact must be made within 3 business days of your subscription purchase and your refund request will be subject for review.

Please Note: Refunds can never be provided more than 30 days after the initial purchase date regardless of your activity on the site.