The formula for calculating kinetic energy (KE) is KE = 0.5 x mv2. Here m stands for mass, the measure of how much matter is in an object, and v stands for the velocity of the object, or the rate at which the object changes its position. Your answer should always be stated in joules (J), which is the standard unit of measurement for kinetic energy. It is equivalent to 1 kg * m2/s2. If you are solving a problem where the mass isn’t given, you will have to determine the mass yourself. This can be done by weighing the object on a balance and obtaining the mass in kilograms (kg).  Tare the balance. Before you weigh your object, you must set it to zero. Zeroing out the scale is called taring.  Place your object in the balance. Gently, place the object on the balance and record its mass in kilograms. If necessary, convert grams to kilograms. For the final calculation, the mass must be in kilograms. Oftentimes, the problem will give you the velocity of the object. If this is not the case, you can determine the velocity by using the distance an object travels and how long it takes to cover that distance. The units for velocity are meters per second (m/s).  Velocity is defined by the equation, displacement divided by time: V = d/t. Velocity is a vector quantity, meaning it has both a magnitude and a direction. Magnitude is the number value that quantifies the speed, while the direction is the direction in which the speed takes place during motion. For example, an object’s velocity can be 80 m/s or -80 m/s depending on the direction of travel. To calculate velocity, simply divide the distance the object traveled by the time it took to travel that distance.
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One-sentence summary -- Know the formula for calculating kinetic energy. Determine the mass of an object. Calculate the velocity of the object.

Q: To illustrate how each of the central tendency functions works, we’ll use a series of ten small numbers. (You won’t likely use actual numbers this small when you use the functions outside these examples.)  Most of the time, you’ll enter numbers in columns, so for these examples, enter the numbers in cells A1 through A10 of the worksheet. The numbers to enter are 2, 3, 5, 5, 7, 7, 7, 9, 16, and 19. Although it isn’t necessary to do this, you can find the sum of the numbers by entering the formula “=SUM(A1:A10)” in cell A11. (Don’t include the quotation marks; they’re there to set off the formula from the rest of the text.) You do this by using the AVERAGE function. You can place the function in one of three ways:  Click on an empty cell, such as A12, then type “=AVERAGE(A1:10)” (again, without the quotation marks) directly in the cell. Click on an empty cell, then click on the “fx” symbol in the function bar above the worksheet. Select “AVERAGE” from the “Select a function:” list in the Insert Function dialog and click OK. Enter the range “A1:A10” in the Number 1 field of the Function Arguments dialog and click OK. Enter an equals sign (=) in the function bar to the right of the function symbol. Select the AVERAGE function from the Name box dropdown list to the left of the function symbol. Enter the range “A1:A10” in the Number 1 field of the Function Arguments dialog and click OK. The average, or arithmetic mean, is determined by finding the sum of the numbers in the cell range (80) and then dividing the sum by how many numbers make up the range (10), or 80 / 10 = 8.  If you calculated the sum as suggested, you can verify this by entering “=A11/10” in any empty cell. The mean value is considered a good indicator of central tendency when the individual values in the sample range are fairly close together. It is not considered as good of an indicator in samples where there are a few values that differ widely from most of the other values.
A: Enter the numbers you want to find the average of. Find the average of the numbers you entered. Observe the result in the cell you entered the formula in.

Article: Elevating the head of the bed by six to nine inches (15 to 23 cm) is recommended for both sleep apnea and acid reflux. You should still be comfortable enough to get a full night’s sleep, so try starting at a lower elevation instead of going straight to nine inch risers. Basic bed risers cost about half as much as specially designed products. However, they don’t have foam that molds to the angle of the feet that results from elevating one end of the bed. If you do go with a basic product, it should still have wells or recesses so the bed feet don’t slip over the edge.Avoid lightweight plastic products, as they’re not as safe as thick, heavy duty plastic, solid wood, or metal options. Cinder blocks, stacks of wood, or even thick books are your cheapest option. While inexpensive, these options aren’t as safe as store-bought bed risers, and many people don’t like how they look. In addition, it might be more difficult to ensure you’re raising the feet to the same height.  Choose the widest blocks possible to reduce the risk of the feet slipping. You can also place non-slip pads, such as those you'd use to keep a rug from moving, under and on top of the blocks to reduce the risk of slipping. One pro is that you can start from a low height and gradually stack more books or blocks until you reach six to nine inches. That way, you can get used to the elevation without having to purchase multiple sets of bed risers.
Question: What is a summary of what this article is about?
Raise your bed at least six inches (15 cm). Use wood, metal, or heavy duty plastic risers with wells. Go with cement or wood blocks for the most affordable option.

Article: Angles can be classified in three ways: acute, obtuse, and right. Acute angles are narrow (less than 90 degrees), obtuse angles are wide (greater than 90 degrees), and right angles are exactly 90 degrees (two lines perpendicular to each other). You can easily identify by eye, the category of angle you are trying to measure. Doing this step first helps you identify which scale to use on the protractor. At a glance, we can tell this angle is acute because it is less than 90 degrees.
Question: What is a summary of what this article is about?
Approximate the measure of your angle.