What is Physics 12: Definition and 43 Discussions

Physics (from Ancient Greek: φυσική (ἐπιστήμη), romanized: physikḗ (epistḗmē), lit. 'knowledge of nature', from φύσις phýsis 'nature') is the natural science that studies matter, its motion and behavior through space and time, and the related entities of energy and force. Physics is one of the most fundamental scientific disciplines, and its main goal is to understand how the universe behaves.Physics is one of the oldest academic disciplines and, through its inclusion of astronomy, perhaps the oldest. Over much of the past two millennia, physics, chemistry, biology, and certain branches of mathematics were a part of natural philosophy, but during the Scientific Revolution in the 17th century these natural sciences emerged as unique research endeavors in their own right. Physics intersects with many interdisciplinary areas of research, such as biophysics and quantum chemistry, and the boundaries of physics are not rigidly defined. New ideas in physics often explain the fundamental mechanisms studied by other sciences and suggest new avenues of research in academic disciplines such as mathematics and philosophy.
Advances in physics often enable advances in new technologies. For example, advances in the understanding of electromagnetism, solid-state physics, and nuclear physics led directly to the development of new products that have dramatically transformed modern-day society, such as television, computers, domestic appliances, and nuclear weapons; advances in thermodynamics led to the development of industrialization; and advances in mechanics inspired the development of calculus.

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  1. susan_khan

    How to Calculate Speed of Head of Driver After Collision?

    A 0.045 kg golf ball is hit by a driver. The head of the driver has a mass of 0.15 kg, and travels at a speed of 56 m/s before the collision. The ball has a speed of 67 m/s as it leaves the clubface. What is the speed of the head of the driver immediately after the collision? I'm not sure...
  2. Bookdigger

    I'm Stuck on Solving This - R2 Confuses Me

    I tried solving this and realized that I have no idea what r2 is and I can't just insert an equation there
  3. rudransh verma

    Intro Math Maths needed to advance my physics understanding

    I am a 10(high school)+ 2 years student. I have a basic knowledge of calculus, trigonometry, algebra, arithmetic. I need to advance as an undergraduate to start my physics journey. I want a mathematics book for physics which if it will cover some basics in early chapters will be of much help...
  4. E

    I am having some difficulties solving a combination circuits problem

    I'm having difficulties finding the current for a 9-ohm resistor only, not the 20-ohm My attempt was to find the voltage of a 20ohm resistor which is V = (0.75A)(20-ohm) = 15V. I got the 0.75A by adding the currents of the two resistors (8-ohm and 16-ohm) together that were in parallel and it...
  5. F

    Looking for feedback on selecting a good topic

    Homework Statement Choose a technology such as MP3 players, laser, medical imaging, or another that interests you (Other than the cell phone). Research the internet and find out how it is related to the physics of light and waves. In approximately 100-150 words, write a paragraph explaining the...
  6. F

    Projectile Motion Problem (Physics 12) -- Apple core thrown from a tree

    Homework Statement A child sitting in a tree throws his apple core from where he is perched (4.0m high) with a velocity of 5.0 m/s [35 degrees above horizontal], and it hits the ground right next to his friend. A) How long is it before the apple core hits the ground? B) How far from the base...
  7. M

    Physics Investigatory Project for grade 12?

    Hello, I've submitted 8 topics already but sadly it was all rejected, I could really use some help to look for investigatory projects about physics
  8. C

    Motion of Charged Particles in Electric Fields

    Homework Statement This is the question: An electron at rest of mass 9.11 × 10−31 kg is accelerated through a potential difference of 350 V. It then enters some deflecting plates of 50 V with dimensions as shown. Calculate the distance x (deflection of the electron) (Charge on an electron is...
  9. M

    Physics 12: Acceleration of Proton in B-Field

    Homework Statement [/B] A proton is accelerated from rest at the positive plate of two charged parallel plates with a potential difference of 2000 v. After leaving the plates through a small hole in the negative plate, it enters a uniform magnetic field of 0.50 T in a direction perpendicular to...
  10. A

    Work, Gravitational Potential and Kinetic Energy, Spacecraft

    Hi guys. I'm new to this forum so I'm not sure if I'm posting this in the right place or correctly, but I was totally stumped on a Physics 12 question as I was studying for my exam. The question is: An explorer spacecraft is descending towards Mars using a rocket engine for braking. The...
  11. UchihaClan13

    Classical Where Can I Find Volume 1 of 'Advanced Problems in School Physics'?

    Hi there,everyone I am in need of the following book "Advanced Problems in School Physics" Volume 1( By Cengage Learning) I have volume 2 But no matter how hard I try, I can't get the first volume( it's either out of stock or is currently unavailable etc.) I would greatly/deeply appreciate it if...
  12. D

    Coefficient of Friction of Fixed Atwood Pulley

    Homework Statement Hi, I was wondering how you would isolate for and calculate the coefficient of friction in an Atwood pulley, with one fixed pulley, with two masses hanging off of it on either side. There is no table or surface that the masses are touching or resting on, they are both...
  13. Marleycake

    Position-time graph/velocity graph help

    Homework Statement Hi, I just started my kinetics course a few days ago and have a few questions about how to graph this and maybe help me out with some of the equations involved, I'm completely new to this and I got this test sheet a few days ago. thanks a lot guys...
  14. D

    Relative Velocity of Ball on Moving Board

    Homework Statement A ball rolls with a velocity of 14 mm/s [W] on a board that is being pulled [E 60o N] at 20.0 mm/s. What is the velocity of the ball relative to the floor? b = ball x = board f = floor Homework Equations V_bf = V_bx + V_xf The Attempt at a Solution I tried to work through...
  15. Julian102

    Electric intensity at orthocenter of a triangle.

    Homework Statement At the vertices of a triangle there are + 5C, -7C, -3C of charge respectively. What is the electric intensity and direction at its orthocentre? Homework Equations Each side of the triangle is 1 mm in length. The Attempt at a Solution [/B] I failed to find the distance of...
  16. A

    How to Calculate Electric Field at a Point for Physics 12 Electromagnetism?

    Homework Statement Homework Equations Let e be electric field. e=kq^2/r^2 Fe=qe The Attempt at a Solution I have no idea what the steps to solving this are, I am looking for a quick outline on the first few steps only. I calculated the magnitude of each point's electric field at 0.144.
  17. A

    Physics 12 Electric Energy Question

    Homework Statement A proton starts at rest and travels through a potential difference of 8000V. What's it's final speed. Homework Equations ΔEe+ΔEk=0 ΔEk=-ΔEe Ee=qV The Attempt at a Solution I know how to find the correct magnitude, but I am getting the wrong sign. Ek=-ΔEe 1/2mv^2=-qΔV...
  18. abm77

    Waves -- Find the lowest possible values for m_r and m_v

    Homework Statement Two slits are separated by a distance of 4.40x10-6m and illuminated with two monochromatic light sources with wave lengths of 600nm (red) and 400nm (violet). The mr bright fringe of the red light coincides with the mv bright fringe of the violet light. What are the lowest...
  19. pdaniel

    Earth's Electric & Gravitational Field: Direction, Shape & Height

    Homework Statement Earth actually has an electric field of 1.0 x 10^2 N/C at its surface pointing toward the center. (b) Compare Earth's electric field and gravitational field in terms of i) direction ii) shape iii) how it changes as height increases. c) What is the largest mass that can be...
  20. G

    Calculating Potential Energy and Velocity in Newton's Cradle Lab

    1. This lab is based on 'Newtons cradle' () I can't link to the actual lab video because that requires my password and username...not that I don't trust you guys/gals but its a public site. Anyway, he let's the first ball go at 3.0 cm above it's equilibrium position and asks for me to calculate...
  21. G

    Physics 12: Power Output Calculation for Accelerating Object

    A 5.0 kg object is accelerated from rest to 6.0 m/s while moving 2.0 m across a level surface. If the force of friction is 4.0 N, calculate the power output I used d=vt to find the time which was .33sec then i put that into P=Fd/t and had (49-4)(2)/.35 and got 270 Watts
  22. G

    Physics 12 energy/work question

    A heavy box of mass “n” kg slides 12.0 m along a straight friction less 30 degree incline. If the box starts from rest at the top of the incline, what is its speed at the bottom. (hint: think energy) I used Fd=1/2mv^2 which was msin30(12)=1-2mv^2 and I canceled the masses then came...
  23. G

    Calculating Work Done by a Horse Pulling a Wagon with Friction on a Level Road

    :How much work did a horse do that pulled a 200 kg wagon 80 km along a level road if the effective coefficient of friction was 0.060? I used W=Fd to find the work (W=1960*80000=156800000) then I got the force of friction by ff=(coeff)Fn and got (.06)*1960=117.6. I then got the...
  24. G

    Physics 12 vector (sin law, cos law) problem

    :An object explodes into three equal masses. One mass moves East at a velocity of 15.0 m/s. If a second mass moves at a velocity of 10.0 m/s 45.0 South of East, what is the velocity of the third mass? I drew these vectors tip to tail, then used cos law to determine the velocity...
  25. G

    Physics 12 momentum and vector question

    A 40000N truck moving West at a velocity of 8.0 m/s collides with a 30000N truck moving South at a velocity of 5.0 m/s. If these two vehicles lock together upon impact, what is the initial velocity of the vehicles after the collision? I first found the momentum's of both trucks...
  26. G

    Physics 12 momentum question

    A stationary lift raft of mass 160 kg is carrying two survivors with masses of 55 kg and 72 kg. They dive off the raft at the same instant, the 55kg person East at 4.4 m/s and the 72 kg person North at 4.2 m/s. AT what speed and in what direction does the raft start to move? So i started off...
  27. G

    Physics 12 law or conservation of energy

    Q:A 46 g steel marble collides obliquely with an identical stationary marble, and continues at 55 to its original direction. The collision is perfectly elastic. What is the angle between the direction taken by the target ball and the original direction of the incident ball? I know the...
  28. G

    Physics 12 energy, work question

    Q:A sandbag stops a 12 g bullet which was traveling at 860 m/s. The bullet penetrated a distance of 24 cm into the sand? a) How long did it take the bullet to stop? b) What average force acted on the bullet? first i used ∇p=Ft so 10.32=18490t t=5.6*10^-4 sec then i put that into e=1/2mv^2...
  29. G

    Physics 12 Momentum and work, energy question

    Q:A boy of mass 45 kg is traveling without a seat belt, in a car with a velocity of 14 m/s. When the car stops suddenly, he is stopped by the windshield in a distance of 0.024m. What force does he exert on the windshield? i set the impulse of the vehicle (mv)= to FD (because (delta)E=W=Fd)...
  30. S

    Suppose the mass of the Earth were doubled (Physics 12)

    Homework Statement Suppose the mass of the Earth were doubled , but it kept the same density and spherical shape. How would the weight of objects at the Earh's surface change? Homework Equations Fg=Gm1m2/r^2 The Attempt at a Solution g=G2m/r^2 g=19.59817612 g/g(on Earth - 9.8)...
  31. M

    Egg toss design project with target for Physics 12 ISU

    Homework Statement Need to build a container to hold a Large grade A egg that must have maximum dimensions of 25cm x 25cm x 25cm. Score for marks is based on Score = (200 - Distance from target in cm)/Mass of container with egg. The egg is thrown from at least 1 m above the ground and 2 m from...
  32. S

    Physics 12 Help- Electomagnetism and Torque

    Homework Statement If you were given this question: http://img40.imageshack.us/img40/975/picture7we.png how would you go about solving it? Homework Equations I found a formula that makes this question seem a lot easier. Torque = NIAB. however, this formula is not on the formula...
  33. S

    Physics 12: Acceleration and Distance Problem Solution

    Homework Statement a car accelerates in a straight line from rest ot a velocity of 80km/h in a time of 6s Homework Equations what is the acceleration of the car? how far did the car travel in this time? The Attempt at a Solution Now I am trying to convert 80km/h to m/s, so that...
  34. P

    Should the driver make a run for it at an intersection with a yellow light?

    Homework Statement A person driving her car at 50km/h approaches an intersection just as the traffic light turns yellow. She knows that the yellow light lasts only 2s before turning red, and she is 30m away from the near side of the intersection. Should she try to stop, or should she make a...
  35. F

    Physics 12 help for homework

    Homework Statement A golfer is a putting on a green, and takes 3 strokes to "hole the ball" On the first putt the ball rolls 5.0m due east. The second putt travels 2.1 m at an angle of 20.0 degrees north of east. The third putt is 0.50m due north. What displacement (magnitude and direction...
  36. J

    Projectile Question Physics 12

    Homework Statement Hi, I am just wondering if someone can check if this is the correct answer for this question. Thanks in advance 1 . A projectile is launched with a speed of 48m/s at an angle of 34 degrees BELOW the horizontal. Calculate the speed an direction of the projectile 2.5...
  37. L

    Physics 12 Journal help, please

    Hey, any ideas/input would be very helpful! Thanks! 1. It is sometimes said that water is removed from clothes during the spin cycle by centrifugal force throwing the water outward. Explain if this is correct by describing what centrifugal force is and how the spin cycle helps "dry out" the...
  38. J

    Physics 12 Kinematics Question

    Physics 12 Kinematics Question.. Please Help! Homework Statement A ball rolls off the top of a 12.5m building with a speed of 3.4m/s. How long does it take to hit the ground? What is the range from the base of the building? Homework Equations V = V0 + at V2=V02 + 2ad Avg V = (V = V0)...
  39. S

    Courses Where Can I Find More Challenging Physics Questions for Grade 12?

    Hey, I'm in Grade 12 Physics in York Region School Board (Bayview SS) and I was talking to one of my friends who took the course and he said that the questions the teacher will give is much harder than anything in the book. In other words I'm looking to find more challanging questions for the...
  40. S

    Solve Physics 12 Problem: Helicopter of 5500 kg Reaches 5500 m in 900s

    I have a quick physics 12 problem A helicopter of 5500 kg starting from rest reaches a height of 5500 m with a velocity of 210 m/s. If this happens in 900 seconds, what is the Power? i'm not sure how to do this one, i used P = W/t and solved for work being Ef - Ei. but is there no initial...
  41. S

    Various Physics 12 problems

    EDIT: 1 question left http://i2.photobucket.com/albums/y15/seiferseph/4.jpg tried a couple different things, nothing worked. I'm not sure what to do with the force at the top, where to take the torques, how to use the friction (which way does the force go?) and which angle to use for the...
  42. I

    Calculating Electron Mass from Magnetic Field and Potential Difference

    I don't know if this is the place to post this, but This is a simple Grade 12 Physics question that I have been working on for about half an hour now. For those who don't normally use this notation, 2E10 = 2X10^10. 2E-2 = 2X10^-2 "A magnetic field of 3.4E-3T deflects electrons into a...
  43. X

    Welcome Paul Ask Your Physics 12 Questions Here

    Hey every one, This is my first post on the forums glad to know i have such smart people here who can help me when I am stuck. right now I am taking physics 12 in British columbia. For some reason I am really having trouble grasping the topic of 2d kinematics. any pointers in helping me...