All Questions
14
questions
0
votes
0
answers
393
views
Relationship between height and mass?
Objects with different masses are placeed on the horizontal surface of a table. The objects are then raised to different heights above the tabel. The gain in gravitational potential energy of each ...
-1
votes
1
answer
283
views
Increase in the internal energy of the block-surface system due to friction [closed]
I found this question:
https://plainmath.net/force-motion-and-energy/13968-block-dragged-horizontal-surface-acting-degree-horizontal-displaced
and I'm trying to understand why he used this formula to ...
0
votes
2
answers
272
views
Limitations Of Work-Energy Theorem
Consider the given system which shows a chain $AB$ of length $l$ and the end $A$ is held at rest.
Suppose we release the chain at time $t=0$. How do we find the velocity of the chain when the end $A$ ...
- 117
1
vote
1
answer
2k
views
How much vertical weight/height do I need to store 33 kWh of energy? [closed]
My question is the feasibility of a vertical mechanical weight battery, but unlike previous questions, I wanted to give a precise scenario and see if my math is right (which I doubt)
First, it takes 1....
- 21
0
votes
2
answers
420
views
How much more net energy do I use walking up hill?
I have a question regarding work done / energy done.
Say a $70\mathrm{kg}$ man walked $100\mathrm{m}$ on a horizontal surface as a constant speed, is it correct to assume the energy done by this man ...
0
votes
1
answer
315
views
Finding G.P.E. of a system of particles
we want to calculate the P.E(potential energy) of a system containing 3particles p1,p2,p3.the point of observation is P.so now we should add up the P.E at P due to p1,p2,p3 to get the net potential ...
- 289
0
votes
1
answer
300
views
Particle oscillating through a ring due to gravity
While looking through previous US Physics Team F=ma tests, I came across this interesting question that I cannot solve. The question is as follows:
A uniform circular ring of radius R is fixed in ...
- 13
-5
votes
1
answer
5k
views
Energy question [closed]
It is from an exam but it's worth going on here
I know the answer from the mark scheme. but I don't know why
To be honest, they all look like true statements to me...
1
vote
2
answers
234
views
Using gravity to generate power
I believe that a 17.18 lb weight pushed off a 32ft ledge is one horsepower being that 550 foot pounds/ second is equal to 1hp and G is 32ft/s squared. Thus dropping 17.18 lbs for 32 feet equals 746 ...
- 11
1
vote
3
answers
752
views
Is it possible for man to break Earth into 2 parts? [closed]
Many countries have extreme devastating nuclear weapons. Also they have weapons in very large numbers.
I want to ask that
Is it possible for man to break earth into 2 parts with the help ...
- 239
4
votes
1
answer
2k
views
Work performed by a stationary object in a gravitational field "on Earth" [duplicate]
I was thinking about this problem:
How much work is required to hold an object stationary in a gravitational field?
or:
How much energy is required to keep an object stationary in a ...
- 143
2
votes
2
answers
1k
views
Dynamics of a Vertical Mass-Spring Simple Harmonic Oscillator with Gravity
I am having some trouble obtaining the elastic potential energy and gravitational potential energy of a simple mass spring system.
In this experiment, masses attached to a spring were dropped from a ...
- 175
2
votes
1
answer
42k
views
Needed Energy For Lifting 200 kg weight
I'd like to learn how much energy I need to lift a 200 kilograms weight on normal earth conditions?
For example how much electric power do we need?
I'm not a physicist and not a student and this is ...
- 123
0
votes
2
answers
438
views
Calculating kinetic energy?
Would this be a valid equation to calculate kinetic energy created from a drop from a height:
$$E_{kinetic} ~=~ v_{vertical}tmg$$
Velocity multiplied by time gives distance. Distance multiplied by ...
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