Total # Posts: 659
From previous records a shipping company knows that the cost to deliver a small package within 24 hours is $15.50. The company charges $17.95 for shipping, but guarantees to refund the full charge if the delivery is not made within 24 hours. If the company fails to deliver ...
May 5, 2015
Hello, The pressure P and volume V of an expanding gas are related by the formula PVb=C, where b and C are constants (this holds in adiabatic expansion, without heat gain or loss). Find dPdt if b=1.6, P=12kPa, V=80cm2, and dVdt=20cm3/min. Thus far, I got d(PV)/dt= p(dv/dt) + V...
April 10, 2015
A 2.0kg object initially at rest explodes breaking into two pieces of mass 5.0kg and 15.0kg. If the 15.0kg piece moves with a speed 2m/s what is the speed of the 5.0kg piece? A. -6 m/s B. 15 m/s C. -5 m/s D. 20 m/s
April 6, 2015
1.40g each of CO, H2O, and H2 are sealed in a 1.41−L vessel and brought to equilibrium at 600 K. CO(g)+H2O(g)⇌CO2(g)+H2(g)KC=23.2 How many grams of CO2 will be present in the equilibrium mixture?
March 10, 2015
Two blocks are connected by a string on a pulley. One block is on an incline, and the other is hanging. The smooth inclined surface makes an angle of 35 ∘ with the horizontal, and the block on the incline has a mass of 5.7 kg. The mass of the hanging block is m = 4.0kg...
February 25, 2015
Emma os using connecting cubes to make a rectangular model with a height of one connecting cube. With her cubes she can make the model in exactly 3 different ways. If Emma has more than 12 but fewer than 17 cubes how many cubes does she have
February 19, 2015
A rifle bullet is fired at an angle of 28.3° below the horizontal with an initial velocity of 177 m/s from the top of a cliff 52.2 m high. How far from the base of the cliff does it strike the level ground below?
January 6, 2015
At a local high school,560 out of 1060 students voted to support a community fund drive. What percent of the students did not support the fund drive? 47% is this the correct answer?
December 19, 2014
A 590 kg racing car completes one lap in 14.3 seconds around a circular track with a radios of 45.0 meters. The car moves at constant speed. (A) what is the acceleration of the car? (B) what force must the track exert on the tires to produse this acceleration?
December 11, 2014
A ball is thrown vertically upward with an initial velocity of 5 ft/sec from a height of 20 feet. Which function models its motion? i literally am lost and have no idea how to this problem. if i could have help with the steps on how to do the problem and to get the correct ...
November 21, 2014
When Charlotte planted her tomato plant, it grew 3 inches in one week. After 5 weeks, the tomato plant was 23 inches tall. Assume the relationship is linear. Find and interpret the rate of change and the initial value.
November 17, 2014
Fiona and camila took a load of peaches to the farmers market. During the first hour , they sold 1/2 of the peaches plus 1/2 of a peach. In the second hour, they sold 1/3 of the remaining peaches plus 1/3 of a peach. In the third hour , they sold 1/4 of what was left and 3/4 ...
October 26, 2014
A home run is hit such a way that the baseball just clears a wall 26 m high located 118 m from home plate. The ball is hit at an angle of 37 ◦ to the horizontal, and air resistance is negligible. Assume the ball is hit at a height of 1 m above the ground. What is the ...
October 6, 2014
Hello, I require help with my German Next week I'll be starting taking additional lessons to help me with my coursework, but for now, I would be immensly grateful for your help. I've managed to do most of my tasks by myself, however there are some that are just too ...
September 29, 2014
A motorcycle has a constant speed of 21.6 m/s as it passes over the top of a hill whose radius of curvature is 100 m. The mass of the motorcycle and driver is 392 kg. Find the magnitude of (a) the centripetal force and (b) the normal force that acts on the cycle.
September 28, 2014
A ball is launched horizontally at 5 m/s from the top of a 45 m tall building. A man stands at rest 6 m from the base of the building. If there is a 0.3 s reaction time for the man to start moving once he sees the ball launched, find the magnitude of the man's acceleration...
September 28, 2014
Suppose that the swimmer in the figure below has a swimming speed relative to the water of 0.45 m/s, while the speed of the current is 2.0 m/s. If it takes the swimmer 160 s to cross the river, how wide is the river?
September 24, 2014
hill that has a 37.7 % grade is one that rises 37.7 m vertically for every 100.0 m of distance in the horizontal direction. At what angle is such a hill inclined above the horizontal?
August 21, 2014
A highway is to be built between two towns, one of which lies 47.0 km south and 69.0 km west of the other. (a) What is the shortest length of highway that can be built between the two towns, and (b) at what angle would this highway be directed, as a positive angle with respect...
August 21, 2014
There were a total of 2000 tickets sold at a recent sporting event on Saturday. The cost of an adult ticket was $4.00 and a child's ticket was $2.00. The total amount of money collected was $6400.00. How many adult and child tickets were sold at the game?
August 18, 2014
Hi, I need help with MLA citing. This is just an example paragraph but please tell me if Im citing correctly : Tom was sad. Howard states," Tom leaned over the table with disappointment" (Howard 23).
July 29, 2014
How do I graph a slope of 2/3 passing through the point of (-3,-4). Please help. I was given this answer, but I am unsure if it is correct **Since the slope is 2/3, go right up 3 and up 2 and plot another point.
July 28, 2014
I wanted to see if I was solving this problem correctly. A line passes through the point (-3,-8)and has a slope of -2.Write an equation for this line. y=mx+b m=-2 y=-2x+b -8=-2(-3)+b
July 28, 2014
For f(x)=2(x+5)^3 +7 Find and classify the extreme values, determine where the function is increasing and decreasing, where it is concave up and concave down, and any points of inflection. I understand this is using the first and second derivative tests, but I can't find ...
July 22, 2014
A cup of coffee at 90 degrees celsius is put into a 30 degree celsius room when t =0 . The coffee's temperature, f (t ) , is changing at a rate given by f '(t )=-8(0 .8) t degrees celsius per minute, where t is in minutes. Estimate the coffee's temperature when t =...
July 21, 2014
t 0 5 10 r(t)0 90 0 A shop is open 9 AM - 7 PM. The function r(t), gives the rate at which customers arrive (in people/hour) at time t, where t measures time in hours since 9 AM. Suppose that the salespeople can serve customers at a rate of 75 people per hour. At 4 hrs after ...
July 21, 2014
q 0 125 250 375 500 625 750 C'(q) 27 35 41 45 43 46 51 Give fixed cost = 8800 and cost of producing 250 units is 17425, how much would the total cost increase if production were increased one unit, to 251 units?
July 21, 2014
The ABC Self-Concept Inventory has a split- half reliability coefficient of 0.90 and the XYZ Self-Concept Inventory has a Spearman- Brown reliability coefficient of 0.90. And if all factors are equal, which instrument would be chose to use?
April 22, 2014
If an instrument requires some professional judgments in scoring, then the manual should also include information on a. Interrater RELIABILITY b. Corrections of the reliability coefficients using the Spearman-Brown formula c, Both KR 20s and KR 21s d. Test retest reliability ...
April 21, 2014
A sample of oxygen gas was collected via water displacement. Since the oxygen was collected via water displacement, the sample is saturated with water vapor. If the total pressure of the mixture at 26.4 °C is 725 torr, what is the partial pressure of oxygen? The vapor ...
April 15, 2014
Knowing the concentration of a solution allows us to find all of the following except A. the mass of a solute. B. the mass of the solvent. C. the volume of the solvent. D. the concentration of a solution when conditions change.
March 19, 2014
incorrect , the answer is C, The ability of the atmosphere to capture and recycle energy emitted by the Earth surface is the defining characteristic of the greenhouse effect. The greenhouse effect is a process by which thermal radiation from a planetary surface is absorbed by ...
March 13, 2014
Neil gets in an elevator at the 30th floor and it begins to move downward at a speed of 8 feet per second. After 12 seconds the elevator is 240 feet above ground. a. Let y= the height in feet of the elevator 'x' secinds after Neil got in. Write an equation to show the ...
March 4, 2014
Assume that the normal blood buffer contains 0.00080 M carbonic acid and 0.0085 M hydrogen carbonate, the pKa = 6.35 for carbonic acid and the volume of blood in the body is 7.00 L. The blood pH, due to disruption is now 7.20. What is the ratio of [HCO3−]/[H2CO3] now ...
November 11, 2013
If you need to prepare 250.0 mL of a pH 5.00 buffer that has a total buffer concentration of acetic acid + sodium acetate of 0.050M, how many moles of each will you need to prepare the solution? Given solutions of acetic acid and sodium acetate with concentrations of 0.10M and...
November 11, 2013