Difficulty of a Task The difficulty in "acquiring a target" (such as using your mouse to click on an icon on your computer screen) depends on the distance to the target and the size of the target. According to Fitts's Law, the index of difficulty (ID) is given by
where W is the width of the target and A is the distance to the center of the target. Compare the difficulty of clicking on an icon that is 5 mm wide to clicking on one that is 10 mm wide. In each case, assume that the mouse is 100 mm from the icon.
Want to see the full answer?
Check out a sample textbook solutionChapter 4 Solutions
Algebra and Trigonometry (MindTap Course List)
- Weight Gain Zoologists have studied the daily rate of gain in weight G as a function of daily milk energy intake M during the first month of life in several ungulate that is, hoofed mammal species. Both M and G are measured per unit of mean body weight. They developed the model G=0.067+0.052logM With appropriate units for M and G. a.Draw a graph of G versus M. Include values of M up to 0.4unit. b.If the daily milk-energy intake M is 0.3unit, what is the daily rate of gain in weight? c.A zookeeper wants to bottle-feed an elk calf so as to maintain a daily rate of gain in weight G of 0.3unit. What must the daily milk-energy intake be? d.The study cited above noted that the higher levels of milk ingested per unit of body weight are used with reduced efficiency. Explain how the shape of the graph supports this statement.arrow_forwardLogarithmic Equations Use the definition of the logarithmic function to find x. (a) Inx=1 (b) In(1/e)=xarrow_forwardNewton’s Law ofCooling states that the temperatureTof an object at any time t can be described by theequation T=Ts+(T0Ts)ekt, where Ts is thetemperature of the surrounding environment, T0 is the initial temperature of the object, and k is thecooling rate. Use the definition of a logarithm alongwith properties of logarithms to solve the formula fortime tsuch that tis equal to a single logarithm.arrow_forward
- Expanding Logarithmic Expressions Use the laws of Logarithms to expand the expressions. Ina3arrow_forwardLogarithmic and Exponential Forms Complete the table by finding the appropriate logarithmic or exponential from of the equation, as in Example 1.arrow_forwardStride Frequency of Animals Four-legged animals run with two different types of motion: trotting and galloping. An animal that is trotting has at least one foot on the ground at all times, whereas an animal that is galloping has all four feet off the ground at some point in its stride. The number of strides per minute at which an animal breaks from a trot to a gallop depends on the weight of the animal. Use the table to find a logarithmic equation that relates an animal’s weight x (in pounds) and its lowest stride frequency while galloping y (in strides per minute).arrow_forward
- Wealth Distribution Vilfredo Pareto (18481923) observed that most of the wealth of a country is owned by a few members of the population. Paretos Principle is logP=logcklogW where W is the wealth level how much money a person has and P is the number of people in the population having that much money. aSolve that equation for P. bAssume that k=2.1 and c=8000, and that W is measured in millions of dollars. Use part a to find the number of people who have 2 million or more. How many people have 10 million or more?arrow_forwardExpanding Logarithmic Expressions Use the Laws of Logarithms to expand the expression. In(xyz)arrow_forward
- Algebra and Trigonometry (MindTap Course List)AlgebraISBN:9781305071742Author:James Stewart, Lothar Redlin, Saleem WatsonPublisher:Cengage LearningCollege AlgebraAlgebraISBN:9781305115545Author:James Stewart, Lothar Redlin, Saleem WatsonPublisher:Cengage LearningAlgebra & Trigonometry with Analytic GeometryAlgebraISBN:9781133382119Author:SwokowskiPublisher:Cengage
- Functions and Change: A Modeling Approach to Coll...AlgebraISBN:9781337111348Author:Bruce Crauder, Benny Evans, Alan NoellPublisher:Cengage Learning