![]() ![]() Some interesting situations connected to Newton’s second law occur when considering the effects of drag forces upon a moving object. (credit: NASA/Kathy Barnstorff) Terminal Velocity Smoother “skin” and more compression forces on a swimmer’s body provide at least 10 % 10 % less drag. When taking into account other factors, this relationship becomesįigure 6.31 Body suits, such as this LZR Racer Suit, have been credited with aiding in many world records after their release in 2008. We can write this relationship mathematically as F D ∝ v 2. For most large objects such as cyclists, cars, and baseballs not moving too slowly, the magnitude of the drag force F D F D is proportional to the square of the speed of the object. This functionality is complicated and depends upon the shape of the object, its size, its velocity, and the fluid it is in. Unlike simple friction, the drag force is proportional to some function of the velocity of the object in that fluid. Like friction, the drag force always opposes the motion of an object. You feel a smaller drag force when you tilt your hand so only the side goes through the air-you have decreased the area of your hand that faces the direction of motion. The faster you move your hand, the harder it is to move. You might also feel it if you move your hand during a strong wind. You feel the drag force when you move your hand through water. Determine an object’s terminal velocity given its massĪnother interesting force in everyday life is the force of drag on an object when it is moving in a fluid (either a gas or a liquid).Describe applications of the drag force.The simulation below shows one vector decomposed into its x and y components.By the end of this section, you will be able to: If we have an x-y coordinate axis, any vector on this axis can be decomposed into its x and y components. Our mathematical framework for dealing with multiple vectors involves using vector components. Does it differ from the analytically derived slope by less than the uncertainty? There are more details about this process here. $$\textrm$$įind the slope of your linear data and compare it to what the slope should be from your analytical equation. Plot the results (both experimental and anlytical) with the mass of $P_3$ on the vertical axis, and the $\cos(b)$ on the horizontal axis. We can make the data a little easier to work with by plotting the mass as function of the $\cos(b)$ instead. Your plots should like a section of a cosine function. On one graph plot the experimental data from your table along with the analytical prediction of the function you found. In the box below, enter the formula you have found that will predict the mass of Pan 3. It should be something of the form $P_3 = C \cos(b)$, where $C$ is a constant. Using some basic trigonometry, determine an equation that we can use to predict the mass of $P_3$ as a function of the angle $b$, and the mass of $P_1 P_2$ (considered a constant equal to 200g). We would expect there to be some mathematical relation between the angle $b$, the mass of $P_1$ and $P_2$, and the mass of $P_3$ needed to balance the system. Compile the results in a table like this.(Change the positions of both Pans 1 and 2 each time) Repeat the measurement, changing the angles $b$ each time, in 5° increments, until you reach 80°.Experimentally determine the mass needed to hang from pan 3 to put the system into equilibrium.Are they within the expected sensitivity of the instrument? Exp. Report the difference between what you've experimentally measured and what the simulation predicted. This is the sensitivity to weight of the force table. Find the maximum mass you can place in pan 2 and still maintain experimental equilibrium.It's most likely still in equilibrium, right? Now, in Pan 2 add 1 gram and check for equilibrium.Arrange two pulley systems, Pan 1 at 0° and Pan 2 at 180°.Let's measure how precise the force tables are. If the ring remains centered then the system is in equilibrium. If there is no motion, remove it completely. First just lift it but hold it in the ring to prevent large motions. However, this should be done in two stages. If it moves with the pin, the system is NOT in equilibrium and forces need to be adjusted. The first test is to move the pin up and down and observe the ring.Be sure that when you position a pulley, that both edges of the clamp arc snugly against the edge of the force table.Also whenever you change a pulley position, check that the cord is still radial. In that case the cord will not be radial. ![]() When connecting the cords be sure that the hooks have not snagged on a spoke. The central ring has spokes that connect the inner and outer edges.Tension = please log in Instructions for use: ![]()
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