# Tag Info

1

Just a thought on what it has to be less than. Let's make some assumptions. Let's assume that on impact, all of the balls Kinetic Energy is transferred to the liquid. Let's also assume that all of the energy transferred will go into shooting water up. This should give the upper bound on how high the water "tower" will be. The Kinetic energy available on ...

2

I would dispute that we can see through rain. Any line-of-sight that ends on a rain drop is blocked from reaching the distant object. As we look deeper into the field of rain, more lines-of-sight end on raindrops and images of distant objects become less distinct. Eventually, when the probability of a LoS ending on a rain-drop approaches unity, the depth of ...

8

Low density of raindrops is the answer. However, the change we see in the scene due to the rain can be explained with modulation transfer function. Higher spatial frequencies added to the scene, and lower spatial frequencies suppressed with falling raindrops lower the contrast of the image. Courtesy Now to the numbers. Average speed of a falling rain ...

3

Since there is space between the rain drops, some rays of light travel from the building to your eye without hitting a rain drop. Some other rays if light get scattered randomly when they hit rain drops. Your brain sees the building through the haze because the unscattered light always conveys the same image of the building while the scattered light is ...

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You may be interested in this paper by Garg and Nayar which analyzes the visual distortions and other effects produced by rain. The purpose of the paper was to be able to edit rain out of visual detection systems, and to be able to edit rain into computer graphics. Scroll down to section 4.1 Dynamics of Rain, and Figure 5 which shows how individual ...

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Many of the photons coming from nearby objects will travel to your eye without striking a rain drop. However, photons traveling from more distant objects have a greater chance of hitting a rain drop before reaching you. This makes more distant objects seem dimmer or more difficult to see.

3

Most car windows are pre-stressed: during the manufacturing process, a significant stress differential is "baked in" to the window. This means that the inside of the glass is under tension, while the outside is under compression. One result of this is that windows can seem to have colors in them when you view the sky from inside the car using polarized ...

0

A cooler that has ice and water in it will be held at 32 degrees Fahrenheit until all the ice is melted. The rate at which the ice melts depends on the rate at which heat can enter the container. The rate at which heat crosses any thermal boundary can be modeled as: $$\dot Q=\frac{\Delta T}{\sum 1/h_i}$$ Where $h_i$ represent the thermal conductivity of ...

8

To add to Rick's answer: Rick is right that it is only the front wheel that is skidding. Most of the weight is over the main wheels (it is essential that the centre of gravity be close to the main wheels, to ensure the plane does not pitch when the wheels strike the ground on landing.) Only a small amount of weight is on the nosewheel. It would seem that ...

0

Rough Approximation The angles between final trajectories are small enough that we could approximate this as a 1D problem. Let's assume both vehicles decelerated at $a$ after impact. $$d_A=\frac{{V_A}^2}{2a}$$ $$d_B=\frac{{V_B}^2}{2a}$$ The final momentum is then: $$p=M_AV_A+M_BV_B=M_A\sqrt{2d_Aa}+M_B\sqrt{2d_Ba}$$ Conserving momentum: ...

0

The person only needs to be able to counter the force acting on the plane to slow down the movement. The force on the plane is from the wind - it'll be a reasonably big force because the plane presents a reasonably large surface area - but if the person is wearing ice spikes, it's not inconceivable that they could make a difference.

2

Latent Heat Slows Condensing On a micro scale, when a molecule of water condenses out of the air by joining a water droplet it transfers its higher kinetic energy to the droplet warming it. On a macro scale, if all the water tried to condense out of the air at once, the temperature of the cloud would rise to the point where much of the water would want to ...

2

Thermophoresis A temperature gradient induces a force on small particles due to uneven kinetic energy transfers. This processes is called thermophoresis. The hot plastic will create a strong temperature gradient in the air directly above the plastic, forcing particles away from the plastic and allowing them to be entrained in the convective flow also due to ...

39

Simple (Wrong) Analysis Shoes Assuming the coefficient of friction on the ice is approximately the same for the tires and shoes. It would do just as much good to get into the plane as to try to push it. Both would increase the frictional force by at most $\mu\,m\,g$ Having established an upper bound for the effectiveness of pushing we can compare this to ...

0

According to this article (which links another article that has since become a stale link), the issue is that during ringing (and other communications between the phone and the tower) there are pulses of (relatively) high power RF transmission by the phone. Normally, this should not matter. But when an RF signal interacts with a non-linear circuit element ...

1

First of all, the effect is totally real. Here is an example YouTube video how it sounds (and a recipe how to fix it): https://www.youtube.com/watch?v=x5ruAZ4Useg I am actually getting much more melodic sounds from the speakers! ;-) And I have heard the same melodic reactions of PC speakers in many people's scientific talks and even in TV programs. ...

0

TL;DR You would eventually reach the higher velocity, but the hill ends before you get close. No Gear Changes First lets dismiss the notion that the power and torque requirements to ascend a hill at constant speed are different. To ascend a constant grade hill at a constant speed requires the same constant force $F$ regardless of velocity $V$. Let's ...

2

It depends on the TV/Monitor. Cathode Ray Tube The picture for CRT monitors is actually traced out with one beam tracing back and forth over the entire screen. So rather than having a shutter interrupting the entire screen and the entire screen being illuminated normally. There is only a small spot that is illuminated at any given time. The information ...

0

Archimedes: Get a bucket big enough to contain your whole body at the most shrinking position (like a baby in the womb). Take a note for these following weight scale: Strip off all your clothes - fully naked. Weigh your naked body - Record it as $W_n$ Weigh the bucket - Record it as $W_b$ Put the bucket on the weigh scale Fill that bucket with water ...

0

I will give it a shot (actually it is my first seriously answer with math, ha! Sorry for my lousy English!). Let $\vec{J}=\sigma\vec{v}_\text{rain}$ $\sigma$ is the density of rain. Assuming your front windshield is vertical. the raining is uniform at the scale of the area of your windshield. the raining goes vertically. such that when your car is ...

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I am basing this almost completely on the comments above and my own experience of making a "tin can phone" as a kid. The string was pulled as tight as we could get it, on the basis that a loose string, i.e. no tension, would not carry the sound waves very far. But the tension in the string also makes the base of the cup vibrate, increasing your chances of ...

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