Physics Drop 2 is like crayon physics meets draw something. Physics Drop 2 is a fun way of practising physics. With sharing your unique solutions, you can beat your friends.īoth the lover emoji and the lines react to the law of gravity. You will notice there are multiple ways to solve each puzzle, try to find the best solution. You can compete with your friends to win the Physics Drop 2 Lover Cup. When you need, use the hints! There are dozens of brain blasting physics puzzles, with more being added all the time. It includes challenging games for your brain that everyone from children to grown-ups will be able to enjoy by competing with friends! Funny Physics Games!ĭraw the line and shapes freely to solve challenging physics puzzles by rolling the lover emoji. Katherine Wright is the Deputy Editor of Physics Magazine.Draw the lines Physics Puzzle Game! Challenging games for your brain! Funny Physics Games! This research is published in Physical Review Letters. Philippe Brunet, a physicist at Paris Diderot University who studies the behavior of drops, calls the results elegant and says that the mechanism constitutes a “practical way to move liquids within narrow channels.” He notes that the speed of motion demonstrated in the experiments is “rather slow”-the drops move at just a few hundred micrometers per second-but adds that this slowness could be an asset for drug delivery devices that would inject a liquid over a long period of time. “In droplet physics we normally find that wetting and nonwetting drops behave differently.” This universal behavior could be useful for applications where the same pipe has to carry different liquids, for example. “That both types of drop move in the same direction in bendotaxis is surprising,” Vella says. The researchers call this motion “bendotaxis” because “taxis” is a standard suffix for self-propulsion mechanisms of cells and organisms, and the motion here is induced by bending a material. So once again, the drop breaks for freedom. The researchers found that this kind of drop also minimizes its energy by moving toward the open end of the channel. A nonwetting drop, by contrast, pushes the channel walls apart, and its internal pressure is lowest at the channel’s open end. As the drop tries to minimize its surface tension energy by changing its shape, it moves toward the channel’s open end.
For a wetting drop, the pulling force is stronger at the narrow end. This shape change sets up a pressure gradient within the drop that leads to a variation in how strongly it pulls on the channel sides. The narrowing or widening of the channel by the drop distorts the drop’s shape, making it asymmetric from front to back. The cause of the drop motion, the team deduced, is a variation in the pressure-a pressure gradient-along the length of the drop, and this gradient is induced by the liquid-channel interactions. But with water, the coating and drop repelled each other-a “nonwetting” interaction-so the coverslips bent away from each other, making the open end wider.
Physics drop ost free#
The drop spread out, or “wetted,” the glass and pulled on the walls, drawing the free ends of the coverslips closer together, so that the channel tapered toward its open end. With oil, the interaction between the coating and liquid was attractive. Regardless of the type of liquid, all of the droplets moved towards the channel’s open end, with the channel walls bending slightly inward or outward in the process. The team deposited between 10 and 25 microliters of either oil or water into the closed end of the channel and observed the motion of the droplets. The parallel coverslips were rigid enough to form a long channel but were also somewhat flexible. Then they clamped the coated coverslips at one end, holding them apart with a glass spacer a few hundred micrometers thick. To create a narrow channel, the team coated a pair of thin, half-centimeter-wide glass coverslips with a material that repelled water but attracted oil. Dominic Vella and colleagues at the University of Oxford, UK, have now found one such mechanism. But the need for an external force in most such methods has led some researchers to search for alternative strategies in which liquids can propel themselves along a channel. To move fluids through the channels of a microfluidic device, scientists have used temperature gradients, electric fields, and chemical patterns. The mechanism may be useful in lab-on-a-chip technologies. Researchers demonstrate that liquid drops will move themselves along a narrow, flexible channel created by two glass coverslips that are clamped at one end.
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