All Questions
53
questions
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61
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Deriving expression for gravitational potential energy around a mass, $M$, using vectors
(I think my question will be somewhat related to this one: Deriving gravitational potential energy using vectors .)
I know the change in the potential energy associated with a conservative force, $\...
1
vote
1
answer
130
views
Why can we ignore the work done by gravity?
I am working through the problem above, starting with part (d). By the conservation of energy setting the spring in equilibrium as $y_0$ as the difference in length of the unstretched spring to the ...
0
votes
2
answers
50
views
Orientation of gravity force in energy [closed]
My apologies in advance if this is a stupid question.
A 0.20 kg rocket in a fireworks display is launched from rest and follows an erratic flight path
to reach the point P, which is 29 meters above ...
- 179
0
votes
1
answer
382
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A block starts from rest at the top frictionless slide at a height $h_1$ above the ground and leaves the slide perfectly horizontally
A block starts from rest at the top of a frictionless slide at a height h1 above the ground. The block leaves the side moving perfectly horizontally at a height h2 above the ground. The block ...
0
votes
1
answer
213
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Electric Potential, Work, Potential Energy, and Electric Field [closed]
I don't quite understand these concepts. What is the relationship of electric potential with work, potential energy, and electric field?
1
vote
1
answer
824
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Work done for conservative forces is path independent Proof
So I’m looking at the proof for work that is path independent.
There is a line were the integral
Partial derivative V dr from r1 to r2 becomes
Partial derivative V r’ dt from t1 to t2
I’m a bit ...
0
votes
1
answer
263
views
Taylor Example 4.8. Is my reasoning sound? [closed]
This problem has been giving me all sorts of fits. For one, Taylor states that because the frictional force and normal force are forces of constraint, they produce no work. I'm trying to figure out ...
1
vote
3
answers
93
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An object which is thrown up rises to a height $h$ and and is stopped at height $h/2$. What is the work done?
So, I had this question in mind for a few days now, suppose an object of mass $m$ is thrown up by a person.
Now, work done on the object would be stored in the form of potential energy, now it rises ...
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0
votes
2
answers
327
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What is the work done in pushing an object up a slope of mass $m$ to a height $h$?
What would be the work done when an object is pushed up a slope, My teacher recently said that work done on the object would be greater than PE, can someone explain it to me if this is right or ...
- 356
1
vote
2
answers
380
views
Why is the work done by a block into a spring the same from the work done by the spring on the block?
In the following situation:
A 700 g block is released from rest at height h 0 above a vertical
spring with spring constant k = 400 N/m and negligible mass. The block
sticks to the spring and ...
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-1
votes
2
answers
131
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Verifying $W = \int \vec{F} \cdot d\vec{x}$
Verifying formula for Work;
$$W = \int \vec{F} \cdot d\vec{x} \quad(i)$$
Let us consider a very simple scenario; I will solve first by simple Maths and then by calculus.
Scenario 1: (Force vector is ...
- 439
0
votes
2
answers
37
views
Potential energy for an amount of time [closed]
a mass of 10kg is maintained at 1m above the ground for 25s. What is the work done during this time interval?
i know this formula :
$ W = F * d * cos(a)$
but I don't find a formula with the time and ...
1
vote
2
answers
143
views
Part of physics answer I didn't understand, and don't have reputation to ask them. $10\,\text{ms}^{−2}$
When you lift your $2.5 \,\text{kg}$ laptop (a 15-inch Apple MacBook Pro, for example) by a foot, you do work of approximately $2.5 \,\text{kg} \times 10 \,\text{ms}^{−2} \times 0.3 \,\text{m} = 7.5 \,...
4
votes
3
answers
678
views
In this problem, why is the work done by the spring not equal to the line integral of the spring force over its displacement?
Problem statement:
In the given figure, two blocks A and B, each having a mass of 320 grams are connected by a light string passing over a smooth light pulley. The horizontal surface on which block A ...
- 556
0
votes
1
answer
43
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Potential energy to gain elevation
I did a calculation to see how high the energy in a cell phone battery could lift an adult assuming perfect efficiency but something seems way off.
...
- 105