PHYS 1003 Lecture Notes - Lecture 12: Momentum, Net Force, International System Of Units

56 views4 pages

lemonwasp446

31 Oct 2016

School

Department

Course

Professor

For unlimited access to Class Notes, a Class+ subscription is required.

Document Summary

If we need to find the com (centre of mass) of an object which has circular symmetry, then it is better to use circular polar coordinates. Well, we already know how to convert between the (x,y) and (r, **checking if the given centre of mass is in the centre + com of a sphere are all further applications of the above concept. As objects interact with each other, we need to be able to describe this process in terms. The concept of linear momentum is one of the most important ones in physics of conservation laws. This is the pure definition of momentum, it has a very precise meaning in physics. The linear momentum itself is a vector quantity , which the equation for it is: However it does not apply in certain situations: It does not apply in quantum mechanics (at the atomic level), where particles with.

Related Questions

QUESTION: How do I derive Equations 3, 4a, and 4b? Helpandexplanations are greatly appreciated!

Please refrane from answering if you are unfamiliar with MSExcel and inputing formulas for Cells. Thanks.

NOTE, you may need to save images to desktop to view in a largerscale.

Part b: Collision in Two-Dimensions

The law of conservation of momentum is true for any and everydirection. So, for an isolated system, the momentum in the x, y andz directions or any other direction does not change.

Consider two objects colliding in deep space. Since the two objectstogether can be considered an isolated system, the total momentumof the system (the sum of the momenta of the two objects) isconserved in both the x and y directions. That is

pi-x-total=pf-x-total or pix1+pix2=pfx1+pfx2

pi-y-total=pf-y-total or piy1+piy2=pfy1+pfy2

If we assume object one is moving in the x-direction, object two ismoving in the y-direction and the collision is perfectlyinelastic,
we can rewrite these equations as

m1*vix1=(m1+m2)vfx

m2*viy2=(m1+m2)vfy

These equations can be solved to find the x and y components of theobject's velocity after the collision. The magnitude of vf can befound using the Pythagorean Theorem. The direction of the objectsafter the collision can be found using the inverse cosinefunction

Î¸=cos-1(vfx/|vf|)

Since cos-1 outputs an angle between 0 and Ï radians, we must useÎ¸new=2Ï-Î¸old if vfy is negative to get a correct value. Use thebuilt in function 'if' to find the true value of Î¸. Afterwards,convert the angle into degrees using the built in function'degrees' .

i) Fill in the missing values in the table on the bottom usingformulas to find each value

This is the half of the tablethat is full so far

A = Mass1

B = Velocity initial 1

C = Mass2

D = Velocity intial 2

E = M2/M1

F = Vi2/Vi1

This is therest of the chart that needs formulas

G =Pi-x

H =Pi-y

I =|Pf|

J =Vf-x

K =Vf-y

L =|Vf|

M =Î¸

N = Î¸ if Vi2< 0

O = Î¸(degrees)

In order to solve the problem you must refer to the first partwhich i already solved and I am 200% sure of the answers, however Iam stuck on the second part and I need help asap. Please do not getscared when you look at this problem and thank you soo much inadvance.

A wheel 75 meters in diameter is mounted vertically on an infinitefrictionless plane at the origin. The infinite frictionless planehas a grid of Cartesian coordinates on it. The moment of inertia ofthe wheel is mr^2. The mass of the wheel is 2000kg. There is anengine connected to the wheel that can produce a torque of 2.34x10^6 Nm. There is a 50 kg object attached to the circumference ofthe wheel that is attached to the wheel with a remote releasemechanism. The wheel is placed on the origin so that the plane ofthe wheel contains the point x=50 meters and y=86.8 m. The wheel ispositioned so that the object is just above the plane at the 6o'clock position. The engine is engaged and begins to apply thetorque to the wheel at 12:00 noon on March 1, 2011. The wheelbegins to rotate in the counterclockwise direction. The torque isapplied for 4 x 10^4 revolutions. At that point the object isreleased from the wheel and a 75 Newton motor accelerates theobject in the direction it is released. The motor is fired for 2.34x 10^4 seconds. (the following questions i have already answered)What is the angular velocity and rotational KE of the object justbefore it is released? (answer for that is 6.39 x 10^2 rad/sec and5.89 x 10^11 J). What angle does the path of the object make withthe x axis? (answer is 60.05 degrees). Where is the object on theinfinite frictionless plane when the motor stops (what are itscoordinates....answer is x=4.85x10^8m y=8.40x10^8m). What is thevelocity and linear KE of the object when the motor stops?(5.91x10^4 m/sec and KE= 8.73 x 10^10J). How much work was done onthe object up until the time the motor stopped? (8.73 x 10^10J).(Hint: the mass of the wheel is 2050 kg while the torque is appliedand the object is attached).

YEA I know what you are thinking at this moment. Difficult right?Please give it a chance and have faith in yourself. Here is thepart I had difficulty with:

After the engine stops firing the object is turned around so thatthe engine can be used to stop the object. The motor is fired atits rated thrust to stop the object. Unfortunately it malfunctionsand shuts down after an hour and the object coasts from then on. Atthe end of an hour of coasting it encounters a ramp that is 2000meters high and slopes up at an angle of 20 degrees. The objectclimbs the ramp and flies off the ramp into the air when it reachesthe end of the ramp. It strikes the plane and digs a crater 5meters deep in the plane and comes to a stop. How far from the endof the ramp does it land? Where does it land on the plane (as incoordinates)? What is the resultant velocity of the object and whatis the acute angle of the resultant velocity with the plane when itstrikes the plane? What is the KE of the object when it hits theplane? What date and time is it when the object lands on the plane?How much work was done on the object to stop it? How long did ittake to stop? What was the deceleration of the object in m/sec^2?What was the force on the object in Newtons to stop it?

If you are from MIT I have faith that you can do this. I am only ajunior in high school taking first year physics that is not evenAP. My teacher is from MIT and said he did this kind of stuff whenhe was there. Please please please help me! I'm desperate.

PHYS 1003 Lecture Notes - Lecture 12: Momentum, Net Force, International System Of Units

Document Summary

Get access

Related textbook solutions

Physics: Principles with Applications

Related Documents

PHYS 1003 Lecture 14: 14. Momentum and Impulse Collisions

PHYS 1003 Lecture Notes - Lecture 13: Elastic Collision, Kinetic Energy, Inelastic Collision

EXSS1018 Lecture 12: Week 12 Notes

Related Questions