Homework Statement
Weight suspended by 3 cords. 1 from the weight goes up vertically to the knot. The next goes left 30° below horizontal and the last goes to the right 45° above horizontal.
Homework Equations
f=ma
The Attempt at a Solution
I don't think I've ever worked a problem...
A spinning flywheel is lowered into a gravity well using an elevator.
Energy flows from the flywheel into the elevator motor (which functions as a generator in this case).
The energy is red shifted by gravity, and equivalently by centrifugal force. To be more specific the force part of...
Homework Statement
A spaceship accelerates with constant acceleration to 120 m / s within 10 seconds after launch from Earth.
Imagine that one of the astronauts who weighs 77 kg sits on a bathroom scale while the Launch takes place.
What does the scale show during the launch ?
Homework...
I find I'm biased towards heavy things. I realize this is unreasonable, as a heavier object will not always be of better quality, but I still find that I prefer a heftier object even they wouldn't necessarily benefit from it. Here are some examples of some things I prefer to be heavy:
bed...
http://www.odditycentral.com/pics/tran-van-hay-the-man-with-the-worlds-longest-hair-dies-at-79.html
The man is reported to have the longest hair in the world, they claimed that his hair was measured at 6.8 meters long but never been measured officially. But what I'm skeptical about this was...
Homework Statement
An Atwood's machine consists of two masses, m1 and m2, connected by a string that passes over a pulley.
If the pulley is a disk of radius R and mass M, find the acceleration of the masses.
Express your answers in terms of variables m1,m2, M, R, and appropriate constants...
Homework Statement
An assembly shown in the picture, GH , HK, HNL are three cables. the mass of box L is 52Kg,
a) determine the mass of box K in order to make angle theta as 25 degrees
Homework Equations
Fx=0
Fy=0
The Attempt at a Solution
Fhn x cos(25) = Fhg x cos(0)
fhn x...
First I would like to appologize for my english, I'm from belgium and I don't often use it to speak about physics.
Second, I don't know if I'm in the good thread to speak about that.
Ok, I need a little help,
I have a problem where an object slidind on a incline plan.
I would like to know...
Hi,
The weight on Earth is F = m*g with g = G*M/(r+h)² with G = 6,6742 e-11, M mass of Earth and r the altitude or radius of Earth and h local altitude. M = 5,9736e24 kg. r = 6371000 m.
With 2 masses M1 and M2 of 1kg each at altitude h = 0 m, the weight is g*2 = 2*9.82245719295718826387 =...
I'm browsing through some acceptances posted by prospective graduate students here: http://www.physicsgre.com/viewtopic.php?f=3&t=4274
and there are some guys with very close to 4.0 GPAs and great GRE scores along with pretty good research experiences and letters of recommendations that are...
Homework Statement
Julie tightened herself fastened a set of bathroom spring scales to a platform and went down a 30 degree slope. No friction was present and the platform supporting the scales was HORIZONTAL. what fraction of her true weight was indicated by the scales?
The Attempt...
Homework Statement
A man is flying a kite. The string of the kite makes an angle of 50 degrees with respect to the horizontal and exerts a pull of 15 Newtons. A small bird decides to sit on the kite and causes the kite to reach a new equilibrium position with the sting at 30 degrees with...
I know this question maybe a bit funny, others will call this post BS. But just assume if any object, having a size that ten times larger than Earth and having infinite weight, can the Earth resist such pressure? I recalled somewhere mentioned that Earth, theoretically, can support weight...
Homework Statement
http://data.imagup.com/10/1146555432.jpg
Homework Equations
Force applied on the weight=F*(MA).
The Attempt at a Solution
i chosse the E system ...it has the greater mechanical advantage (MA)=3.
MA(of A)=1, MA(of B)=2,MA(C)=2,MA(D)=2,MA(E)=3..
I hope my...
Weight on a Scale Down an Incline vs. True Weight
Homework Statement
Judy fastened a set of bathroom spring scales to a wedge shaped skate board as shown and coasted freely down a 30 degree slope. The wheels were well oiled and the platform supporting the scales was horizontal. What...
Homework Statement
http://www.physics.ox.ac.uk/olympiad/Downloads/PastPapers/BPhO_PC_2008_QP.pdf
Question 8
Homework Equations
f=ma
The Attempt at a Solution
Sure since f=ma
A) would have force of 0, since there is no acceleration
B) force would be 800N
C) force of 0N
D)...
Hello there :) First I'm sorry for my English it might be kinda bad !
I Have a little question about Weight and Pressure, Hope this is the right place.
Here in this image we have 3 samples, A, B and C.
They are 3 different types of shapes fulled with a liquid (let's say water)
Talking...
Homework Statement
Without numbers, identify how you could find the apparent weight of motorcycle to be 5 times that of the actual weight. The motorcycle is going up a loop the loop with a velocity of v.
Homework Equations
Fnet = mv^2/r
Fg = mg
The Attempt at a Solution
Fnet = mv^2/r...
Hi,
I'm interresting about the weight of the support of the pendulum with an initial speed. It is the http://en.wikipedia.org/wiki/Pendulum but with an initial speed. The mass come at top with straight initial speed and after turn around the pendulum. I attempt to have the weight of the...
I'm designing a bucket pump for a water well I'll be attaching a pumpjack to. I'm just a regular shop guy so I was kind of stumped on a question of how much upward pressure will be required to move the water up the drop pipe. If the pump cylinder is the same diameter of the drop pipe I figure...
Homework Statement
A person who normally weighs 200 lbs is standing on a scale inside of an elevator. The elevator is moving downwards at a constant speed of 7.0 m/s and then begins to slow down at a rate of 4.9 m/s^2. Before the elevator begins to decelerate, the reading of the scale is...
I don't understand conceptually how something accelerating down weighs less. For example, the elevator example of course if you have something with a string and a weight and the acceleration of the elevator increases upward as positive, you get
T - mg - ma = 0
and for acceleration down, you...
Dear friend,
I am getting confused in this question;what i learned till now is that number of proton+number of neutron=atomic mass. But while searching the net i got this equation
atomic mass = mass a x fract a + mass b x fract b. can anyone tell me which is the correct (not approximate)...
Hey guys,
The question gives us N 3-Dimensional Quantum Harmonic Oscillators with :
E=ƩE(i)=Ʃ(n(i)+0.5)(h-bar)w
Where h-bar is the reduced Plancks constant, w is the angular frequency, and the sum takes place over i=1 to i=3N, and (i) is subscript!
Now I believe the microstates of this...
The weight of a body is less when it is submerged in water, due to the upthrust.
But the weight of the water column above the body can be far more than the upthrust(weight of the displaced water).
So is it not that the weight of a body can increase when it is submerged in water?
Hey,
Imagine a frictionless inclined plane situation where the ramp goes up and to the right.
If we put an object on it with any mass m, would it be fair to say that both of the components of the weight are negative? My reasoning is that the x component causes acceleration to the left and the...
i can't figure out how to calculate this. Please help!
How many grams of 6.000 wt% aqueous HF are required to provide a 50% excess to react with 10.0 mL of 0.0236 M Th4+ by the following reaction?
Th(4+) + 4F - → ThF4 (s)
I found the molarity for Th(4+) to be 2.36*10^-4.. I'm not really...
I was wondering, in my class we have been dealing with a lot of equations related to some weight attached to a spring which is attached to a fixed point and has some force being applied to it or something like that. Where exactly is such a thing encountered in real life?
An oblong weight of uniform shape and density is supported horizontally on two supports. The placement of the two supports can be shifted. What is the best way to determine what percentage of the weight is born by each support given any possible arrangement of the supports?
Hi!
I am trying to build a stand with a boom arm for my acting classes and I need to find the weight required to balance it. The problem is that it looks like I was more like a swan when I was swimming in the physics lessons ... no a lot of drops stayed on my plumage ... :)
Help...
Homework Statement
A fisherman in a boat is using a "10- test" fishing line. This means that the line can exert a force of 45 without breaking (1lb = 4.45N). If he accelerates the fish upward at 1.8m/s/s , what maximum weight fish can he land, in Newtons?
Homework Equations
F=ma
The...
Hey all,
Just a quick overview of myself, I have recently started rock climbing (6 month) and I'm finding myself becoming more curious about the technical equipment involved.
I'm finding it hard to word the questions I'm trying to find the answers too. So I'm going to try and I'm...
I have something I need cleared up and looking for some calculation help. I know that water changes density with temperature but does it change due to lack of gravity when the moon is close? So to clear things up I guess I need to know what and how thoes changes will affect the weight of water...
I'm using the app on my iPod that's for myfitnesspal. Great app to help count calories. Also, I'm doing the Zumba exercise program to help with the weight loss/tone up.
Any opinions on all of this??
Homework Statement
Two body move apart by force. Frictional forces are considering. How to calculate the ratio of weight?
m1<m2
Ft1=k*g*m1
Ft2=k*g*m2
Homework Equations
v1(t1)=\frac{F_{t1}-F}{m_{1}}*t_{1}
x1(t1)=\frac{F_{t1}-F}{m_{1}}*\frac{t^{2}_{1}}{2}...
Homework Statement
As you ride on a ferris wheel, your apparent weight is different at the top and bottom. Calculate your apparent weight at the top and bottom of a Ferris wheel, given that the radius of the wheel is 7.2 meters, it completes one revolution every 28 seconds, and your mass is...
Hey,
About Newton's Second Law. To compute our weight on Earth using standard g, we use F=ma replacing F and a with W and g (or -g), respectively. So then from this, I gather that weight is a consequence of gravitational acceleration (and mass). So then, it is appropriate to say that our...
Homework Statement
This is a "DOE" (Design of Experiment) problem. Basically, the construction is fairly simple. 3 pulleys, 2 on either side, and a free pulley with a weight suspended on it in the middle. Picture is available (don't mind my crappy paint skills, rope lengths are all...
Hello,
Thank you all for the help here.
Here we go, I have a known solid weight start of the propellent. I know the PSI of a known volume chamber(After combustion) and Temperature, can I find density?
So example
Bullseye powder has a load of 0.336954332 grams (5.2 grains)
The volume...
Since it has a decimal it would be 20kg * 9.8m/s which equals 196kg m/s^2 = 196N
But the decimal means i have to round two sig figs, which would make it 200N?
A very simple problem, I really don't know why I'm asking it.
Can a man whose weight is 50KG (but powerful arms) lift another man with 70 KG weight using an overhead pulley.
I guess no since the light man is not clamped to the groud, his arm strength will not bear any significance and he can lift only the wieght(on other side of the pulley) equal to his...
Homework Statement
What is the weight percent concentration of a saline solution prepared by dissolving 2.440 mole of KCl in 10 L of water?
Homework Equations
The Attempt at a Solution
This is more of a conceptional question.
Let's say you have 1L of water in a bucket on a weighing scale, which currently reads 50N. If a couple of ice cubes were added, would the weighing scale read 50N + weight of 2 ice cubes?
Side-Notes:
density of the ice < density of water
ice...
Homework Statement
The weight of a baby measured over an 11-month period is given in the weight chart below for this problem.
Weight (lb) Age (months)
6.6 0 (birth)
7.4 1.0
9.6 2.0
11.2 3.0
12.0 4.0
13.6 5.0...
Anyone who knows how to calculate the time a formel car will take from 0-75meter.
The specs are 110HP and weight is 300kg.
I've tried to calculate this without any luck..
I have my own theory on this, but first would like to ask the forum. And the members answering on my other thread, this question is separate but needs to be answered first. Also I have started answering that one.
If use lift 80% of your 1RM, repetition maximum, why is it easier on a barbell...
Hi I just wanted to know what is the mass (in kilogram) of an average car and the mass of an average engine.
This is for my project and I want to know their masses to make a scaled model of a car for my experiment.
Does your weight change in elevator? I have recently found an answer to this question but I can't understand it completely. So, here is the answer : No, your weight is unchanged. To provide the acceleration upwards, the floor or scale must exert on your feet an upward force that is greater in...