Tagged Questions

The tag has no usage guidance.

47 views

Calculate Time from Distance, Initial Velocity and Final Velocity [closed]

How can I calculate the time given the traveled distance, initial velocity and final velocity? I've found some algorithms that include acceleration, but in this case there is constant acceleration. ...
28 views

Scalar invariance and dimensions

I recently read an interesting article on scale in variance http://www.wired.com/2014/08/multiverse/ It discussed how modern physics is suggesting that scalar units really may not apply above the ...
31 views

Does this calculation give displacement or distance?

So we have velocity as a function of time given $\overrightarrow{v}(t)=(1-2bt)k\overrightarrow{r_0}$ where $b,k$ are positive constants and $\overrightarrow{r_0}$ is a unit vector. It is found that if ...
20 views

size at a distance

Can someone help me please. If I held up my thumb at full arms length into the sky. My thumb is the width of an object I am looking at, at 2000 meters away. How big is the object in the sky?
57 views

Projectile motion with air friction force/resistance [closed]

We have to find the x (the distance, if you didn't know that then I'm not sure if you should be doing this problem) that the projectile travel during the time in the air until the time it hits the ...
54 views

79 views

If displacement is 0, why isn't the work performed on an object 0?

Work is force x distance/displacement. The exact definition is something I'm a little confused about since my professor said it could either be distance or displacement. So going with that, if the ...
106 views

Distance from Earth where gravity becomes negligible

This is a basic little problem I thought up when trying to remember some physics, and I wanted to see if it's at all correct: trying to figure out the distance from earth where gravity becomes ...
44 views

Measuring distance in a spaceship moving with 0.5c [closed]

If there are a spaceship moving at a speed of 0.5c that sent a photon when an asteroid was exactly $3\times 10^8$ m away, will the distance between the spaceship and the asteroid when the photon hits ...
35 views

How to calculate the diameter of a moving circle from afar while lacking and knowing some information?

Let's say there is a solid wood wheel with two tires attached at the bottom travelling on a level road towards me while facing me width-wise (as in, the side of it from which you can see its diameter)....
51 views

Can motion be characterized without time as independent variable? [closed]

I was just thinking about speed = distance/time which relatively describes how fast something is moving wrt some still object. So if by some wishful thinking or some coordinate system I remove the ...
88 views

Distance can be zero

Can a distance between two particles can be exactly zero? Example: If I have two opposite charged particles having uniform charge. They will attract each other and the distance between them will ...
52 views

Can a photon be captured in a grid space representation at a fractional Planck position?

Consider a photon, positioned in space in a finite portion of a grid. Any point of the grid is vertically or horizontally aligned, each distanced by a Planck unit. $l_P = 1.616 199(97) × 10−35 m$ ...
121 views

How far do we need to be removed from the earth to show the curvature with a viewing angle between 42 and 48 degrees? [duplicate]

I have seen already a couple of answers but none of them give an exact number of what should be the minimum height where we would be able to record the curvature of the earth All I could find is ...
99 views

Why is the potential energy minimal when the repulsion and attraction force between molecules is 0?

According to this potentialcurve and the other curve(?) the potential energy is minimal when the intermolecular forces equal zero. Why? How should I interprete negative potential energy in this ...
11 views

Blocking Window Distance Estimation in sCMOS Sensor setup

I am trying to establish an appropriate distance between a spectrograph output window and a CMOS sensor. The spectrograph creates a focussed image on the CMOS sensor, but I need to block out some of ...
39 views

When measuring distance how do we know when supernova comes from binary star and not single one?

The way I understand distance is measured for far out objects is by binary star supernova, since at the point of explosion there's is always same amount of energy released. But then supernova can ...
40 views

Calculating position of a particle at time $t$ in a gravitational field

I'm working on a piece of code that is supposed to visualize a particle bouncing up and down from the ground (somehow magically we can give it velocity upwards when it is on the ground). I figured ...
38 views

Distance between two charged particles [closed]

Is there a way I can find a function $r(t)$ that gives me the distance that separates a charge $q$ and another charge $Q$ knowing the initial velocity of both $v_{01}$ and $v_{02}$ and the initial ...
227 views

Is there a minimum distance? [duplicate]

I would imagine there is no limit to how small space can get. Is this correct? I am aware of planck's constant, but cannot objects be closer than Planck's constant is short? Perhaps this question is ...
60 views

Difference between Distance and Space

So I take particle A and place it in space, then I place particle B 1,000,000 light years away from particle A. I strike a line between the two, and measure that line as having a length of 1,000,000 ...
1k views

If UV radiation 1 cm away from the halogen bulb is equal to Sun's radiation, what is the level of radiation 1 meter away?

Halogen light bulbs emit some amount of UV radiation, and some sources consider them dangerous. Here it is written, that UV radiation (of certain types) from a particular halogen bulb was equal to the ...
33 views

65 views

Can meters measure a distance in higher dimensions?

Consider meters as a unit of measurement. Meters can, of course, be used to express distance across a two-dimensional plane. E.g. The distance from your chair to the door is 2 meters. Meters can also ...
36 views

Formula for speed of rigidly connected objects with one “turning off” of the line?

In the diagram below I have two objects traveling up the diagram on the black track at some speed s, separated by distance D connected by a breakable rigid rod. Further along the straight-line track, ...
87 views

Derivation of a kinematical equation [duplicate]

My question is, we can calculate distance of free falling objects with the equation of $d = \frac{1}{2}gt^2$ where $d$ is distance in meter, $t$ is time in seconds, but I wonder how we achieved this ...
330 views

Is displacement in circular motion a chord or an arc?

When taking the displacement between two points along a circular path to calculate its velocity, do you take the length of a chord connecting the two points or do you take the length of the arc ...