The work tag has no wiki summary.
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1answer
305 views
Work and Area under a Curve relating to Hooke's Law
If it takes work W to stretch a Hooke’s-law spring (F = kx) a distance d from its unstressed length, determine the extra work required to stretch it an additional distance d (Hint: draw a graph and ...
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0answers
13 views
Work on Ferromagnetic Object Due to Solenoid
I've been going through some equations and such trying to determine the work done by a solenoid on a ferromagnetic object. I have the following:
Magnetic field due to solenoid:
$\vec{B} = ...
1
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0answers
43 views
How to solve state parameters using these givens for an ideal gas?
In a thermodynamic turbine using air as an ideal gas, given that you have a known inlet temperature value $T_i$, a known exit pressure value $P_e$, a known inlet and exit velocity $V_i$ and $V_e$, a ...
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0answers
40 views
Problem in average height
Let, diameter of cylinder hole of height 30m and diameter 2m filled with water. In a book, when author tried to find out the power for lifting all of the water then he used average height. why is ...
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0answers
79 views
How would a physicist move? [closed]
Let's assume that Johnny Physicist has decided to move from his poor dingy second story apartment, into his much deserved home. Without making modifications to the existing structures? What would be ...
1
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0answers
32 views
Is energy applied by the muscle when it holds a body in the air? [duplicate]
Possible Duplicate:
Why does holding something up cost energy while no work is being done?
We all know the following Newtonian formulas:
PotentialGravitationEnergy=m*g*h
Kinetic Energy = ...
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2answers
69 views
Centripetal Force Acceleration
Suppose you want to perform a uniform circular motion . Then a body performing uniform circular motion horizontally needs an acceleration $= \frac{v^2}{r}$ at each point on the circular path with ...
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1answer
69 views
Why work to change velocity from 0 to 20 km/h is less then from 20 to 40? [duplicate]
Imagine spaceship in vacuum with mass = 1. At beginning, it has velocity 0, and kinetic energy 0.
$$W_1 = 0$$
Then, it turns on its engine, and changes velocity from 0 to 20 (delta v = 20). It's ...
0
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1answer
130 views
Is resistance to motion directly proportional to the speed of a moving object?
Power is known to be equal to the force x velocity (P=FV).
Im solving a question that states the following :
Car with engine working at 32 kW, mass of 1 tonne, travels at a constant speed of 40m/s ...
0
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1answer
215 views
Energy used to stop / slow an object
I'm trying to workout how much energy (if any), I use (imagining me as an efficient machine rather than a complex bio-mechanical human) when I lower or catch a weight. I understand that when I push it ...
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1answer
1k views
How much work is needed to compress a certain volume of gas?
I want to know the formula (and what does the symbols stand for) for how much work is needed to compress a certain volume of gas?
0
votes
1answer
69 views
System moves away from equilibrium $\rightarrow$ it has energy added?
Suppose there is an isolated system $A$ at time $(-\infty, t_1)$, whose entropy is $S=S_{max}$, i.e. it is at thermodynamical equilibrium.
Between moments $[t_1, t_2)$ the isolation is violated and ...
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1answer
58 views
Work done by Static friction
Here $v1$ is relative to the block on which sphere is pure rolling but static friction isn't $0$ as of now .
In the following diagram, is work done by static friction $0$ ?, since the point of ...
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votes
1answer
33 views
Work done by complex field on complex plane
A force field is given by $F = 3z+5$. Find the work done in moving an object in this force field along the parabola $z = t^2 + it$ from $z = 0$ to $z = 4+2i$.
I don't understand why conjugate ...
0
votes
1answer
67 views
About the work done by gravity to pull the object down to the earth surface
The following question is from an physics exercise and I know the answer and the way to solve the problem but just curious why my own way doesn't work. The question is asking "A 2500kg space vehicle, ...
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3answers
247 views
A chain 64 meters long whose mass is 20 kilograms is hanging [closed]
A chain 64 meters long whose mass is 20 kilograms is hanging over the edge of a tall building and does not touch the ground. How much work is required to lift the top 3 meters of the chain to the top ...
0
votes
1answer
130 views
Power, Force Velocity
In any case, if the force and power is constant , does velocity also need to be constant? If no, can you tell me a case.
Further can this be extended for non-rigid bodies.
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0answers
49 views
Work And Energy Question [closed]
$H = 3\text{ m}$,$m=2\text{ kg}$
The right side is rough.
I want to figure:
what is the coefficient of friction $\mu$?
How high and exceed the maximum return on the plane right body?
I know ...
0
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0answers
36 views
Work required to pull capacitor plates apart when connected to battery [closed]
For (a), I just use $F = k \frac{Q_1 Q_2}{r^2}$, then (b) $W = - \Delta U = - qE \Delta d$, correct so far? But how do I do (c)?
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0answers
35 views
What is the total work done in this problem? [closed]
A 1800 kg trick airplane is 450 m in the air. At this point the plane takes a dive
with an initial speed of
42 m/s and accelerates to 64 m/s, dropping
a total distance of 120 m.
(a) Using the ground ...
0
votes
1answer
83 views
Energy needed to lift and bring down an object
A mass of 0.5 Kg needs to be moved from point A to another point (B) which is 1 meters above point A. The time for this movement should be 0.2 seconds, then the mass is kept at position B for another ...
0
votes
1answer
59 views
How to find work done due to friction [closed]
The force F=40N is applied on a 10kg block at an angle of 36 with the horizontal. The block moves a distance of 15m. If the surface is frictionless. If the coefficient of kinetic friction is 0.25, ...
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2answers
102 views
How do you tell what forces do no work?
The total mass of the children and the toboggan is 66 kg. The force the parent exerts is 58 N (18 degrees above the horizontal). What 3 forces/ components do no work on the toboggan?
I said the ...
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0answers
45 views
Work, energy and friction [closed]
A car loaded with bricks has a total mass of 18kg and is pulled at a constant speed by a rope. the rope is inclined 30 degrees with above the horizontal, and the cart moves 20.0 m on a horizontal ...
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0answers
26 views
How did scientists come up with Work? What was it fundamentally defined as? [duplicate]
Now before I get into the questions I want to make a couple of things clear, I know that there were similar questions like this and I've been through (what i think is) all of them and none of the ...
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2answers
122 views
Measuring work done by gravity over non-constant gravitational acceleration
A question from an example from a MIT Classical Mechanics Lecture on Work.
Here's the given definition for gravitational potential energy (~32:00): "The ...
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votes
1answer
69 views
What is the difference of work $W$ and thermal energy $Q$ in thermodynamic Stirling-process for ideal gas?
What is the difference of work $W$ and thermal energy $Q$ in thermodynamic Stirling-process (in simple form) for ideal gas?
I think that you need work to preserve this process and you bring thermal ...
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votes
0answers
79 views
How can I measure the calories consumed in daily activity? [closed]
From a nice question here:
How are the calories in food calculated?
I can roughly understand how people provide the data of calories in certain food.
However, I am still confused about 2 things.
1) ...
0
votes
0answers
52 views
Need help with physics [closed]
The net force along the linear path of a particle of mass 320g has been measured at 13.0cm interval, starting at x=0.0, to be 26.0, 28.4, 28.8, 29.6, 32.4, 40.1, 46.6, 42.2, 48.8, 55.7, 55.8, 60.2, ...
0
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0answers
141 views
Air condition and net heat [closed]
I have attempted to solve a problem, but my answer is not quite the same as in the book. Thus, I would really appreciate it if someone could confirm/disconfirm whether or not my solution is correct.
...
-1
votes
2answers
345 views
Work done by the air resistance [closed]
A ball of mass 0.37 kg is thrown upward along the vertical with a
initial speed of 14 m / s, and reaches a maximum height of 8.4 m.
a) What is the work done by air resistance on the ball? b) ...
-3
votes
1answer
82 views
Work done by an ideal, massless, inextensible, non-relativistic string [closed]
what is the work done by an ideal, massless, inextensible, non-relativistic string in an isolated system with respect to a reference frame at rest? If it is zero, then why?
-6
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4answers
343 views
Violation of Newton's Second Law (?)
Here the big circle denotes the circular path of a stone(small circle on path) tied to a string from the centre of the circular path .
This is COMPLETELY HORIZONTAL
At an instant the velocity in ...
