Fall Definition and 921 Threads

Hey Everyone, I'm currently looking at designing a device that would allow people to escape from working at heights quickly and safely in the event of an emergency (up to 33 m) I know there are some products on the market already but since I don't have a great deal of experience with them...

A ball of mass m is released from rest at x=0. Air resistance is expressed as R = kv2 , where k is a positive constant and v denotes velocity. Derive an expression for the speed in terms of the distance x that it has fallen. Identify the terminal v. I know I have to start with ma = mg -...

Homework Statement A one stage booster rocket has a Xo of 0m and a Vo of 0 m/s. The rocket takes off with a constant acceleration until 5 seconds when the boosters turn off and goes into free fall. The rocket is set to explode the instant it hits it's max height. The max height is 1200m...

This is my first post on here, so I apologize in advance if I'm in the wrong section or something. I was thinking about having this as my schedule for the fall semester. -Analysis I -Discrete Mathematics -General Physics I -Data Structures I'm not sure if I'm being overly ambitious...

Homework Statement Consider the system below. The 2.50 kg mass compresses the spring (k = 805 N/m) a distance of 0.230 m from equilibrium. The mass is then released from rest. It slides a total distance of 1.20 m on the table top where it feels a force of kinetic friction of 5.60 N before it...

Homework Statement A rock is thrown vertically upward with a speed of 17.0 from the roof of a building that is 60.0 above the ground. Assume free fall. In how many seconds after being thrown does the rock strike the ground? Homework Equations I used v^2 = vinitial^2 + 2a(y - yinitial)...

can somebody explain to me what is geomagnetic that recently run down to earth? i really want to know.

So I'm studying for the physics GRE and plan on taking it this April. While I understand the deadline for admissions to most universities is right up until the semester begins, I also understand it is a first come, first serve deal. Are most slots going to be filled by May, when the scores...

Homework Statement The problem is to find the velocity as a function of time, given the following; the object is in free fall and its initial velocity is zero. The formula given for the air resistance is: a = g - kv, where g is acceleration d/t gravity, k is a constant, and v is velocity...

Hi everyone, I am doing a lab report about free fall, but I have to find the terminal velocity for the balloon, but I don't know if I can use the formula velocity = Distance / Time because I have 10 measures from free fall ( 0.2 m - 2 m) , and I have the time that it took to hit the ground...

[b]1. Wondering if there are any different equations out there for free fall drop. [b]2. The only one I received was H=1/2gt^2 [b]3. I don't know if there are any others, someone said ΔX=ViTf+1/2aTf^2, but I don't think that's for free fall?

Homework Statement The problem is to construct a model out of ordinary materials such as paper, blotting paper, foil, tights and so on, that is supposed to fall along about 3 metre long runner with as longest time as possible. (with the inspirations like maple seed)The Attempt at a Solution I...

I understand that the moon doesn't fall down because it is in an orbit around the Earth. Is this orbit created by warped space due to the mass of the earth?

Homework Statement A whee and axle having a total moment of inertia of .0002 kg*m^2 is caused to rotate about a horizontal axis by means of an 800g mass attached to a cord wrapped around the axle. The radius of the axle is 2 cm. Starting from rest, how far must the mass fall to give the wheel...

Does a falling object hit the ground with a force of its mass times "a" of gravity? Hi, When an object is falling through the air and in free fall with no air resistance, the applied force is the net force on the object: the object's mass times the acceleration due to gravity (or...

I'm still struggling with spacetime curvature. I want to know about the spacetime intervals in the following scenario: An apple is cut loose from a tree, but is still attached by an unstretchable rope that is measured to be 10 meters by the tree observer. (I'm ignoring all but relativistic...

Homework Statement What is the ratio between times for the aliens to hit the floor. you have two spheres of equal density throughout. One has a radius R and the other 1/2R. An alien falls down one and takes time T, the other it falls down in time t. In the second on, time t, half of the mass...

"Yes! The first snowfall of the year" - someone, somewhere at least once a day Is this statement true?

I have an egg drop project, in which we make a container on the ground that can cushion the fall of the egg. The limits are: 8 cm height max, and 45 x 45 cm box max area and the egg must not break even if it bounces out after hitting the container. It'll be dropped first from a height of 2...

It would probably require some sort of leg attachment to relieve the stress on the knees and ankles. Is it within the realm of possibility?

Homework Statement A ball is thrown horizontally at 16m/s from a clifftop 65m above the sea level. Find the time to land Homework Equations distance = Vi*t + at^2/2 The Attempt at a Solution I separated x and y components. And tried to plug them in this formula. I thought...

Homework Statement A kangaroo jumps a height of 2.8m. How long was it in the air? Homework Equations v=v0+at x=x0+v0t+(1/2)at^2 v^2=v0^2+2aΔx The Attempt at a Solution -2.8 = -4.9t^2 .57 = t^2 t = .76 s (down) 0 = v0^2+2(9.8)(2.8) 54.88 = v0^2 v0 = 7.408 0 = 7.408-9.8t t = .76 (up) t...

Wgat would a "light clock" measure in free fall? I've read in a couple of different books that the similarities between acceleration from gravity and rockets or whatever is only local. Both books said one of the reasons is because with acceleration from gravity two objects in free fall starting...

Homework Statement A particle of mass m falls from rest from height h above the ground. The retarding force per unit mass due to air resistance is kv^2 where k is a constant and v is the velocity of the particle a) write and simplify the equation of motion for the particle b) find an...

Hi, I was watching a hot air balloon show, and one of the demonstrations was someone dropping a ball out of a rising hot air balloon. If a hot air balloon is rising at let's say 19.6m/s, and you drop a ball directly down, will the ball continue to rise for two seconds because it has an...

Homework Statement Well, that's all, my mid-term exam came a question that asked me: if a body with mass of 50 kg was weighed on a scale that is inside an elevator in free fall, how much will it weight? I supposed that the same it would weight on the surface, since gravity never stops...

In my honors course we are covering kinematics concepts. There was this problem which stumbled me but then I figured out what I did wrong. I just want to make sure my concept was right. Here is the problem... A diver springs upward with an intial speed of 1.8 m/s from a board that is 3 meters...

Flicking through quite a few topics here, I have seen that everyone says we can't get to see anything fall into the black hole as it would take ∞ time for us. Now, I'm a bit bugged here. Can someone explain me why it is like that. Also, haven't we seen stars fall into black holes through...

Would anyone know how to determine the area that a drag shield would have to be to allow an object above not to experience no more then .001 Gs? The drag shield that I was thinking about is just a flat sheet attached to the bottom of the top object by a string. Would this even be possible?

I assume this is the right forum to ask this question Based on what I think I know, the Earth completes one full orbit of the Sun in approximately 365.25. Every four years we have a Leap year that adds one day. This I understand. What confuses me is how can Fall begin more than 24 hours...

Problem 17.3 in the "problem book in relativity and gravitation" states: "Show that once a rocket ship crosses the gravitational radius (horizon) of a Schwarzschild black hole, it will reach r=0 in a proper time tau less than or equal to pi*m, no matter how the engines are fired." My...

Homework Statement A juggler throws a ball just so it reaches the ceiling at 3.0 meters. (3m above hand) How do I solve for initial velocity? Homework Equations The Attempt at a Solution

Male Fall Fashion...really? Ok, I want to know how many men want to wear this shirt. Do these guys look mad because they're wearing the same outfit, or because they had to wear the shirt. Are those wild animals?

does a person feel weightlessness or any differences when he make a free fall under gravity of different values say 10m/s^2 or 25 m/s^2. Also it is said a person float in empty space is similar to a free fall. Free fall means it speed accelerates, then it would reach an infinite speed if it...

http://www.facebook.com/AGUFallMeeting?sk=wall&filter=2#!/AGUFallMeeting?sk=wall Just wondering. I'd like to know how it's like and if students are allowed.

May be this question has been asked multiple times here i was just unable to search it by topic or search term. The Question is if every thing is falling towards the sun (i.e planets). Why planets are not falling towards sun in a spiral fashion and ultimately crash into sun ? This may be...

Hello, I am a math and physics double major and a junior at Michigan State University. I have already taken introductory physics, the first semster of classical mechanics, a course in thermodynamics and modern physics, and linear algebra (along with the basic calculus and diff eq courses) I...

I want to major in aero. engineering and mathematics. Over fall semester I will be taking Object-Oriented Programming, Calc/Analytic Geom I, and General Physics I lecture and lab. I really enjoy math and want to take any courses that will improve my math skills that is why I am taking a...

Is this schedule for the fall too heavy? :(( -Intermediate Mechanics I -Intermediate E&M I -Linear Algebra -Fundamental Mathematics (intro proof class for math majors taken after Calc III) -General education course (irrelevant) Total: 15 hours It's...

Hey all, I'm a CCC student right now pursuing a career in Aerospace Engineering. Right now my GPA is a 3.7 and I only intend for it to go higher. It would probably be a 3.8-3.9 if my Chem teacher didn't screw me over last semester, but that's besides the point. :P This fall I'm taking...

Would I be able to get into any PhD Program for applied math? Would you please recommend some PhD and/or masters (with funding) programs to apply to? I'll be graduating in Spring 2012 and unfortunately, my undergrad institution only funds for an extra semester, so my only choice is to apply to...

The Murdoch empire has had to http://www.bbc.co.uk/news/business-14142307" is this the end of the company that bought us the appalling Fox news and authorised despicable journalist tactics?

Homework Statement when g = constant , time = v / g if g varies how do I get t ? One electron is at rest at r0, 3600 km from surface of Earth (r), 10.000 km from center. g(r) = 9.8 m/s^2 , g(r0) = 4, Δ PE = 2.25 x 10^7 1) If it fell in a vacuum, after how many seconds...

Homework Statement A scaffolding is rising at 1.0 m/s when at a height of 50.0 m , then the man on the scaffolding drop a can. determine: a. the time needed for the can to reach the ground . b. what is the final velocity ?Homework Equations note: g=-9.8 m/s the letter o in the equation...

I just need some clarification on this. It is well known that a balloon filled with helium will rise since helium is less dense than air, but what if the balloon were to stay the same weight, but the elastic itself has become much stronger, thus we could concentrate the helium even more...

Is it a linear system? Casual system? Please explain why and how.

Hello, I was wondering under what conditions does free fall need to comply to in order to take effect? I am pretty certain that for an object to be in free fall it needs to be void of any friction, but what about air resistance? Or is air resistance a form of friction? Thank you in advance.

The released last seconds of the fall of a body of the road 3 / 4 of fame is. According to this time how many seconds of falling down? please solve this so quickly . . . (in 3 minutes)

So I am going to be a senior this fall double majoring it mathematics and economics right now my schedule is for the fall is: Topology (5 units) Game Theory (5 units) Poverty/Public Policy (5 units) and most likely going to be grading for vector calculus or number theory. I...

Summer has started and I know a lot of college students have already made their schedule for fall. Post them here! I'll start... Engineering Mechanics Thermal Science Nuclear System Dynamics/Control Numerical Methods and Fortran Nuclear Engineering Lab I'm also considering adding...