Seven and one-half percent of a group of 640 motors are found to be overloaded. How many are not overloaded?
Seven and one-half percent of a group of 640 motors are found to be overloaded. How...
An exercise room has six weight-lifting machines that have no motors and seven treadmills, each equipped with a 2.5-hp (shaft output) motor. The motors operate at an average load factor of 0.7, at which their efficiency is 0.77. During peak evening hours, all 13 pieces of exercising equipment are used continuously, and there are also two people doing light exercises while waiting in line for one piece of the equipment. Assuming the average rate of heat dissipation from people in...
Twenty people apply for seven jobs that are available at Fly-By-Night Aircraft Manufacturing Co. a. In how many different ways could such a group of seven people be composed?b. Twelve of the applicants are men and the rest are women. How many of these seven-person groups have exactly three men? C. How many of these seven-person groups have exactly three men or exactly three women? d. What is the probability that a group of seven selected at random will have exactly three men or...
. A political discussion group consists of four Democrats and seven Republicans. Three people are selected (at random) to attend a conference. a. In how many ways can three people be selected from this group of eleven? b. In how many ways can three Republicans be selected from the seven Republicans? c. Find the probability that the selected group will consist of all Republicans.
A 52-kg woman eats a 640 Calorie (640 kcal) jelly doughnut for breakfast. (a) How many joules of energy are the equivalent of one jelly doughnut? _________ J (b) How many steps must the woman climb on a very tall stairway to change the gravitational potential energy of the woman-Earth system by a value equivalent to the food energy in one jelly doughnut? Assume the height of a single stair is 15 cm. _________ stairs (c) If the human body...
Some dried beans with a 14C/12C ratio one-half of the current value are found in an old cave. Part A How old are the beans? [Archaeological Radiocarbon Dating, p. 355 in the textbook] The half life is 5730... I tried multiplying it by 2 to get 11460... but that is incorrect apparently.
Like any other C# method, constructors can be overloaded. Show how to create two public constructors-one with no parameters, and one with a parameter called sal-that both set the value for the property Salary within the following class: class Employee { public double Salary; }
Some fossil bones containing 1/32 of their original amount of carbon-14 are found. How many half-lives have passed? How old are the bones? (HINT: The half-life of carbon-14 is 5,730 years. If 1/8 of the original amount of carbon-14 was present, 1/8 = 1/23 or 1/(2x2x2), therefore 3 half-lives would have passed and therefore, the bones would be 5,730 years x 3 = 17,190 years old)
3. a) In an experiment with sound waves in a tube, one group of students found resonant frequencies at 540 Hz, 720 Hz, and 900 Hz. What is likely the fundamental frequency of this series? List at least one other resonant frequency they should be able to find. b) Another group of students is also experimenting with sound waves in the same length tube and finds resonance at 270 Hz, 450 Hz, and 630 Hz. One student in the group...
There are seven boys and three girls on a team. The coach must select four people from this group to participate in the championship. a. How many four-persons teams can be formed from the group of ten students? b. In how many ways can four boys be chosen to participate in the championship? c. What is the probability that four boys are chosen for the team? d. In how many ways can three boys and one girl be chosen to...
50% of the nuclei in a radioactive sample decay in one half life. What percent decay in four half lives?