All Questions
32
questions
-1
votes
1
answer
103
views
How to Find Trajectory of Particle?
Let’s say I have a particle, and I know all the forces acting on it at every position. (Let’s say the particle is in an electric/gravitational field to simplify the mathematics involved.) Now, is ...
0
votes
1
answer
34
views
Space-for-time Derivative Substitution in Solving for Elliptical Orbit
I am currently working on a simulation of the Newton's Cannonball thought experiment, in which a stone is launched horizontally from atop a tall mountain at a high speed (in the absence of air) and ...
2
votes
2
answers
126
views
How to show that a radially symmetric central force is conservative?
Let $U\subseteq \mathbb{R}^3$ be open and $f:U\to\mathbb{R}^3$ be a radially symmetric central force, that is, a force field such that
$$f(p) = -g(r)u_r$$
where $r=|p|$ and $u_r$ is the unit vector ...
- 369
1
vote
0
answers
40
views
Force to Inflate a ball underwater [closed]
How much force is required to fully inflate (with air) a beach ball that is 6 feet in diameter at depths of 200 feet underwater?
- 11
0
votes
2
answers
588
views
Intuition behind a line integral over a vector field
I have seen answers to this question on this site already, though I still do not understand what line integrals and there results represent and would appreciate an oversimplified description. I have ...
- 3
0
votes
0
answers
12
views
Issue with work vs force for calculating spring constant [duplicate]
Lets say I have a spring with spring constant k. I put a 10kg weight on the spring and it compresses the spring one meter before stopping. We know that at this point the downwards force is equal to ...
0
votes
2
answers
178
views
How do we show that the work done by a variable force (in one dimension) is the area under the $F$ vs. $x$ curve?
In my physics textbook, to show that work is the area under the $F$ vs. $x$ curve, the author first writes the relation $dw = F dx$. This part makes sense to me. From there, the author writes, $$W = \...
- 1
0
votes
2
answers
83
views
Kinematics confusion regarding sign of integration
I was solving some problems regarding non-inertial frames, and Newtonian mechanics in general, when I faced a major doubt regarding one of the seemingly simple topics, and I'd appreciate it if someone ...
- 1,771
2
votes
4
answers
633
views
Work done by a vector field (Force field) on a particle travelling along a curve
Assume a particle travelling along a curve, the work done by any Force field on the particle while moving along a curve is given by the line integral of $\vec{\bf{F}} \cdot \vec{\bf{dr}}$, but shouldn'...
- 367
1
vote
1
answer
56
views
Why could we only divide the displacement $x$ into arbitrarily many subintervals instead of dividing the force $F$ when calculating the work done? [duplicate]
The definition of work done in moving the object from a to b using integral is $$W=\int_{a}^{b}f(x) \,dx$$
where the force F is a function of displacement x, namely $F=f(x)$
It is makes so much sense ...
- 421
2
votes
1
answer
67
views
Forces along and perpendicular to a curve
A uniform rope of length $l$ is suspended from two hinges, making an angle of $\theta$ with the horizontal at the hinges. Find the depth $d$ of the lowest point of the rope.
Similar questions include ...
- 23
26
votes
14
answers
4k
views
Explaining how we cannot account for changing acceleration questions without calculus
For context, I am a high school physics teacher.
I am teaching students about the basics of electromagnetic force between two point charges. The equation we use is $F=\frac{kq_1q_2}{r^2}$.
This gives ...
1
vote
2
answers
81
views
Is it possible to lift an object from rest with constant power?
This is inspired by the following question.
Consider some object which I want to lift from rest with a constant power throughout the whole process; the power I apply when lifting the object from rest ...
- 6,611
3
votes
0
answers
125
views
How did the Lagrangian and Hamiltonian theories of motion inspire the idea that forces should be treated as one-forms instead of vectors?
On page-5 of this paper1 by E. Minguzzi titled "A geometrical introduction to screw theory", he writes:
Who adopts this point of view argues that it should also be adopted for forces in ...
- 7,980
1
vote
3
answers
142
views
Having difficulties deriving the formula for the force acting upon a dam with height $H$ and width $L$
I was recently fiddling around with the derivation of the formula for the force acting upon a dam with height $H$ and width $L$, which in my textbook is derived by integrating the term $dF=p(z)Ldz$ ...
- 185