# What is Intro to physics: Definition and 19 Discussions

In physics, the special theory of relativity, or special relativity for short, is a scientific theory regarding the relationship between space and time. In Albert Einstein's original treatment, the theory is based on two postulates:
The laws of physics are invariant (that is, identical) in all inertial frames of reference (that is, frames of reference with no acceleration).
The speed of light in vacuum is the same for all observers, regardless of the motion of the light source or observer.

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Hi all, So I'm interested in going to university to study Theoretical Physics but it's been a couple years since high school and I've forgotten pretty much everything about what I learned in physics class. I've always been interested in mathematics though so I went and learned calculus a while...
2. ### What is the speed of an object with a momentum of <-1,-2,3>?

Homework Statement Givens: An object with a mass of 2kg has a momentum of p=<-1,-2,3>. The first two questions asked for the magnitude of the momentum and the corresponding unit vector, which i found to be 3.74 and <-0.267,-0.535,0.802> respectively. The next question asks for the speed of the...
3. K

### Three masses in an elevator accelerating downwards

Homework Statement Three masses (m1=3.2, m2=9.6, and m3=6.4) hang from three identical springs in a elevator with a spring constant of 349N/m. The elevator is moving downwards at -3.7m/s and accelerating downwards at a= -2.5m/s^2. What is the magnitude of the net force on the middle mass...
4. ### Forces acting on a box-pulley system in an elevator?

Homework Statement [/B] For this problem, use g = 10 N/kg. As shown in the figure above, a pulley is mounted to the ceiling of an elevator. The elevator is initially traveling with a constant velocity of 1.40 m/s, directed up. The rope (which we assume to have no mass) passing over the...
5. ### Bernoulli's equation and (mostly) sealed containers.

(This is more of a conceptual question than a real homework question; thank you all so much for your help though!) :D 1. Homework Statement Let's say that I have a large soda bottle. I drill a small hole through the side of it, put my finger over it to seal the hole, and fill the bottle up...
6. ### Rotational energy on an incline

Homework Statement A cart whose body has mass M = 1.5 kg is set on four tires each of which has mass m = 0.3 kg and radius r = 0.1 meters. Each tire can be treated as a solid disk with rotational inertia mr2/2. The cart is set on an incline a height h = 1.2 meters high and released. At the...
7. ### Is Introduction to Physics the Same for Undergrad and High School Students?

Hi everyone. I just want to ask what exactly is intro to physics? Is that what undergrad physics students study or is it high school physics? I am currently studying the textbook physics by David Halliday.
8. ### Designing a Self-Supporting Egg Catcher: A Scientific Approach

Hello, I'm looking for any ideas that you geniuses may have! We have to design a device that will catch a (hardboiled) egg from 7 meters high. It can be made from any material/objects but must be under 5 cm tall (the sides can be as wide as wanted) and must be self-supporting. The device will...
9. ### Intro to Physics problem dealing with speed and distance

Homework Statement A bug crawls outward from the center of a CD spinning at 200 revolutions per minute. The coefficient of static friction between the bug’s sticky feet and the disc surface is 1.2. How far does the bug get from the center before slipping? What is the speed of the bug just...
10. ### Grade 11 Intro to Physics question - distance a football travels

Homework Statement How far will a football travel when it is thrown at 62 km/h at an angle of 35° to the ground? Homework Equations V1v = v1 sinθ; Δd= V1v * Δt + 1/2 * (-9.8 m/s^2) * Δt^2; The Attempt at a Solution V1v = v1 sinθ V1v = 17.2 m/s sin35° [up] =9.9 m/s [up] Δd= = V1v...
11. ### Are all material generally covered in Intro to Physics I?

My professors skipped both chapter 11 & 12, Equilibrium & Elasticity and Fluid Mechanics. I'm worried that I will need to know these chapters for later classes or for the GRE. Has your professor skipped material in your class?
12. ### Finding An Initial Speed, Intro to Physics Question

A boy tosses a coin straight up to 2.8 m. Suppose the height when the coin leaves his hand is 1.2 m. What was the initial speed of the coin when it left his hand? I'm just confused as to what equation to use. And I don't know whether to assume the acceleration is -9.8 m/s^2. Thanks.
13. ### Webassign even my ta's didn't know what to do ? and im in intro to physics

webassign even my ta's didn't know what to do... ?... and I am in intro to physics Homework Statement A 33 ohm resistor is made from a coil of Cu wire whose total mass is 12g. (a)What is the diameter of the wire and (b) how long is it ? ( give you answer in m) Homework Equations one...
14. ### Pressure Calculation for a Container with Water and Olive Oil

I have solved this problem but am not sure where I'm going wrong here... Suppose you pour water into a container until it reaches a depth of 20cm . Next, you carefully pour in a 9.7cm thickness of olive oil so that it floats on top of the water. What's the pressure at the bottom of the...
15. ### INTRO TO PHYSICS: Impedence, pitch, vibration, reasonance

EASY STUFF: Impedence, pitch, vibration, reasonance... Please Help! I would really appreciate it if you guys could take a look at these problems I have difficulty with. Thanks a lot. My answers are in red. 1. As impedance decreases, frequency decreases? 2. For the vibration spectrum (of...
16. ### Physics Intro by Dr. Donald Luttermoser | ETSU

Author: Dr. Donald Luttermoser of East Tennessee State University
17. ### Simple intro to physics question

Ok. This is a fairly simple question since it is problem #11 of Chapter 1! Yet, I cannot do it. (Hopefully this isn't a sign of things to come). Anyway, basically the problem goes like this... A monument rises to a height of 192m. You estimate the line of sight with the top of the arch...
18. ### Intro Physics Help for College Freshman: Review Books w/ Solutions

I am struggling with intro physics in my freshman year of college. Are there any decent review books where the solutions are worked out you could suggest to me to help me further my studies. Thank You
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### Intro to physics vector problem

Hi again, This is the question: An explorer is caught in a whiteout while returning to base camp. He was supposed to travel due north 5.6 km, but when the snow clears, he discovers that he is actually 7.8km at 50 degrees north of due east. a)How far and b) in what direction must he now...