Monday
April 27, 2015

Posts by dan


Total # Posts: 949

Physics
A pilot, whose mass is 91.0 kg, makes a loop-the-loop in a fast jet. Assume that the jet maintains a constant speed of 125 m/s and that the radius of the loop-the-loop is 0.478 km. What is the apparent weight that the pilot feels (i.e., the force with which the pilot presses ...
December 24, 2013

Physics
Thank you so much Elena!!
December 24, 2013

Pre-Calc
Using the difference for formula, find the tan 255. Step by step would be appreciated
December 18, 2013

Math Quiz
Math Quiz please help fast Write the following ratio in simplest form: 32 min:36 min (1 point) 8:9 8:36 32:9 128:144 2. Marie saved $51. On Wednesday, she spent $8 of her savings. What ratio represents the portion of her total savings that she still has left? (1 point) 43:8 8:...
December 12, 2013

Maths
Will it be 16x^2-40x+25
November 18, 2013

Maths
(4x-5)^2
November 18, 2013

Maths
(5x+4)(5x-4)=
November 18, 2013

physics
You apply a potential difference of 5.00 V between the ends of a wire that is 2.65 m in length and 0.654 mm in radius. The resulting current through the wire is 17.6 A. What is the resistivity of the wire?
October 20, 2013

Math
Carla and Candice left from the same place at the same time and rode their bikes in the same direction along a straight road . Candice biked at an average speed that was three-quarters of Carla's average speed. After 2 hours they were 28 miles apart. What was the average ...
October 7, 2013

Math
The area of each trapezoid is 3 times the area of one triangle. The area of one triangle is six square units. What is the total area of the figure in square units?
September 23, 2013

Algebra word prob
If you graph the table of values and draw a line through the coordinates, the graph will look like a parabola. Thus the equation is quadratic. Since you don't have a graphing calculator, I will give you the resulting a/b/c values that it comes up with, but the rest is for ...
September 10, 2013

Math
2. True or false. Suppose the slope of a straight line L is -3/4 and P is a given point on L. If Q is a point on L lying 2 units to the right of P, then Q is situated 3/2 units below P. Prove why.
August 27, 2013

physics
The Hyperloop is a hypothetical new fast transport system between cities, which works by launching pods that carry people through a very low air pressure tunnel. The Hyperloop reduces friction between the pods and the tunnel by supporting the pod on a cushion of air. This air ...
August 22, 2013

Statistics
Hola ¿Cuál es el P - value en este problema que escribiste?
July 29, 2013

Math
A circle of radius 1 is drawn in the plane. Four non-overlapping circles each of radius 1, are drawn (externally) tangential to the original circle. An angle γ is chosen uniformly at random in the interval [0,2π). The probability that a half ray drawn from the centre...
June 24, 2013

Math
There are 100 runners, each given a distinct bib labeled 1 to 100. What is the most number of runners that we could arrange in a circle, such that the product of the numbers on the bibs of any 2 neighboring runners, is less than 1000?
June 23, 2013

Math
γ is a permutation on eight elements, though you are not told which permutation it is. If γ is applied to an 8-element set, what is the minimum number of additional times we must apply γ to the resulting set in order to guarantee the set is back in its original ...
June 18, 2013

Physics 1
A body of mass 6kg moving at 8m/s collides with a stationary body of mass 10kg and sticks to it. Find the speed of the composite body immediately after the impact.
June 10, 2013

Math (Algebra)
Thanks Steve!
May 21, 2013

Math (Algebra)
f(x) is a cubic polynomial that satisfies f(1)=f(2)=f(3)=4 and f(0)=0. What is the value of f(7)?
May 21, 2013

Math (Probability)
Please tell the answer. I'm not able to get it. Thanks.
May 21, 2013

Math (Probability)
Bret and Shawn are playing a game where each turn the players roll a 20-sided die fair and then add the number they get to their score. The winner is the player with the highest score at the end of the game (there may be a tie). Before the last turn, Shawn is winning by 10 ...
May 21, 2013

Math (Algebra)
A number is called algebraic if there is a polynomial with rational coefficients for which the number is a root. For example,√2 is algebraic because it is a root of the polynomial x^2−2. The number √2+√3+√5 is also algebraic because it is a root ...
May 21, 2013

Physics
A 15 kg, 1m wide door which has frictionless hinges is closed but unlocked. A 400 g ball hits the exact middle of the door at a velocity of 35 m/s and bounces off elastically, thereby causing the door to slowly swing open. How long in seconds does it take for the door to fully...
May 21, 2013

Math (Combinatorics)
Six boxes labeled 1,2,…,6 are arranged in a line. Seven identical balls are to be placed into the boxes such that for any 1 ≤ k ≤ 6, there are at least k total balls amongst boxes 1,2,…k. How many different placements of the balls into the boxes are ...
May 21, 2013

math
or 9√970/500.
May 20, 2013

math
It's 0.5606068140863.
May 20, 2013

Physics
A 15 kg, 1m wide door which has frictionless hinges is closed but unlocked. A 400 g ball hits the exact middle of the door at a velocity of 35 m/s and bounces off elastically, thereby causing the door to slowly swing open. How long in seconds does it take for the door to fully...
May 20, 2013

Geometry
Perimeter of Rectangle = 2L + 2W where: L = length, and W = width Perimeter = 2(8) + 2 (6)= 28 inches Area of Rectangle = L x W Area = (6in)(8in) = 48 inches squared.
May 20, 2013

heeelp MATH
Yes please Reiny. It would help me a lot. Thanks! :)
May 16, 2013

Math (Geometry)
ABC is a triangle with a right angle at A. M and N are points on BC such that AM is the altitude, and AN is the angle bisector of ∠BAC. If CN/NB=21, what is CM/MB?
May 16, 2013

Math (Geometry)
ABC is a triangle with a right angle at A. M and N are points on BC such that AM is the altitude, and AN is the angle bisector of ∠BAC. If CN/NB=21, what is CM/MB?
May 15, 2013

Math (Geometry)
Thanks hans!
May 15, 2013

Math (Geometry)
A point P is given outside of a circle Γ. A tangent from P to Γ touches Γ at T with PT=45. A line from P cuts Γ at the 2 points A,B. If PA=25, what is the length of PB?
May 15, 2013

Math (Geometry)
ABCD is a parallelogram with side lengths AB=15,BC=10 and ∠ADC=75∘. A point P in the interior of the parallelogram is chosen such that ∠APD+∠CPB=180∘. What is the measure (in degrees) of ∠PAD+∠PCB?
May 15, 2013

Math (Probability)
When Lino submitted an essay for his English class, it was 9 pages long. Lino's essay had errors on pages 2 and 7. If the teacher chose 3 pages uniformly at random to read, then the probability that she didn't read any of the pages with errors can be expressed as a/b ...
May 15, 2013

Math - Maximizing Logarithm
x and y are positive values satisfying x + y = 1/4. When ln(y^2+4xy+7) attains its maximum (subject to the given constraint), what is the value of 1/xy?
May 13, 2013

algebra
12(3+y)=5(2y+8)
May 11, 2013

math
the class room had 100 students.in 200, there were 6 few men than there were woman.how man women were in the classroom in 2010?
May 9, 2013

accounting
A company was recently formed with $ 50,000 cash contributed to the company by stock-holders. The company then borrowed $ 20,000 from a bank and bought $ 10,000 of supplies on account. The company also purchased $ 50,000 of equipment by paying $ 20,000 in cash and issuing a ...
May 7, 2013

Pre Algerbra
I invested $3,000, part at 2% and the rest at 5% simple interest. After 1 year, I earned a total of $117 in interest. How much did I invest at each rate?
April 25, 2013

math
0.941
April 21, 2013

physics
A radio station on the surface of the earth radiates an EM-wave with an average total power of 50 kilo-watts. Assuming the transmitter radiates equally in all directions (not in real life), find the amplitudes Emax and Bmax detected by a satellite at a distance of 100km from ...
April 15, 2013

physics
Four acrobats of mass 61.0 kg, 68.0 kg, 62.0 kg, and 55.0 kg form a human tower, with each acrobat standing on the shoulders of another acrobat. The 61.0-kg acrobat is at the bottom of the tower. If the area of each of the 61.0-kg acrobat's shoes is 370 cm2, what average ...
April 4, 2013

Physics
For safety in climbing, a mountaineer uses a nylon rope that is 55 m long and 0.9 cm in diameter. When supporting a 88-kg climber, the rope elongates 1.4 m. Find its Young's modulus.
April 4, 2013

physics
A window washer is standing on a scaffold supported by a vertical rope at each end. The scaffold weighs 192 N and is 3.4 m long. What is the tension in each rope when the 708-N worker stands 2.40 m from one end? Smaller tension: ___N Larger tension: ___N
April 4, 2013

Chemistry
A 7mL triprotic acid was analyzed and found to contain 0.2572 grams of acid, evidence of phosphate group. Find the molecular weight of the acid, and identify acid. Thank you.
April 3, 2013

physics
I am helping my friend move into his new apartment. During the move, we have to load boxes into the back of his truck. To make it easier to load them, we've set up a metal ramp so that we can slide the boxes up to the deck of the truck. The box shown in the figure has a ...
April 2, 2013

western illinois
102 = 3.14 x 42.25 x h solve for h
March 30, 2013

Calculus
The volume of the 3-dimensional structure formed by rotating the circle x^2 + (y-5)^2 = 1 around the x-axis can be expressed as V = a\pi^2. What is the value of a?
March 27, 2013

Physics
Every once in a while a bird will get hit by a baseball during a baseball game. The longest home runs in baseball land about 500 feet (which is 152.4 meters) from home plate. If these balls leave the bat at a 45 degree angle to maximize their distance, what is the minimum safe...
March 27, 2013

Trigonometry
ABC is a right triangle with AB = 2, BC = 3\sqrt{5}, AC = 7 and \angle ABC = 90^\circ. If \cos \angle BAC = \frac{a}{b}, where a and b are coprime positive integers, what is the value of a + b?
March 27, 2013

Geometry
Determine the number of subsets of A=\{1, 2, \ldots, 10\} whose sum of elements are greater than or equal to 28 .
March 26, 2013

Geometry
ABC is an acute triangle with \angle BCA = 35 ^\circ. Denote the circumcenter of ABC as O and the orthocenter of ABC as H. If AO=AH, what is the value of \angle ABC (in degrees)?
March 26, 2013

Geometry
ABC is an isosceles triangle where AB = AC and BC = 60. D is a point on BC such that the perpendicular distance from D to AB and AC is 16 and 32, respectively. What is the length of AB?
March 26, 2013

physics
A cargo plane is moving with a horizontal velocity of vx = +225 m/s at a height of y = 920 m above level ground as shown in the figure below when it releases a package. Ignoring air resistance, how much time will it take the package to reach the ground? (Express your answer to...
March 26, 2013

Algerbra
8x+7=6 (subtract the 7 from left side) 8x=-1 (divide the 8 on both sibes) x= (-1/8)
March 24, 2013

algebra
D.
March 24, 2013

physics
YOU HAVE TO CHECK If Alice now applies QFT2n and measure, she will still get k with probability 99%. AND If she does as in the previous option, she will get k with probability 99%.
March 22, 2013

math
$8.00
March 17, 2013

Math
I think it should be x<=5/6 1. multiply thru by 5.... 2x-15x+10>=5x-5 2. combine like terms... -13x+10>=5x-5 3. get your variables on one side(-5x from both sides) -18x+10>= -5 4. isolate the variable... (-10..) -18x>=-15 5. /both sides by -18 !!careful!! ...
March 17, 2013

hs geometry
It's a proportion...53/63=x/67 in other words... st.height/st.shadow=tr.height/tr.shadow Solve by cross multiplying...63x=53*67 so x=56.37inches.. Good Luck!
March 17, 2013

math
64t^6 r^5g^3
March 17, 2013

Physics
Consider a pair of parallel plates with a potential difference of 12 V and are separated by 12 cm. What is the potential energy of a 1.0 C charge at point A, exactly 30. cm from each plate?
March 16, 2013

math
44c-4c^3
March 16, 2013

Math
Ms. Sue ???? i could have 0 toppings (that's 15).....or i could have 1 topping (x's 15 flavors) - that's 1215 ...or i could have 2 toppings 81x80(x's 15 flavors) that's 97200 more... Don't i have to get the sum of all of the combinations ??
March 16, 2013

Math
If I have 15 flavors of ice cream and 81 different toppings, how many different combinations could I create (assuming only 1 flavor of ice cream in the container at a time)? I got 36267774588438900000000000 ??? IS THIS RIGHT???
March 16, 2013

Chemistry
The specfic heat of iron is 0.11cal/g C. The heat of fusion of iron, the heat required to convert iron from a solid to liquid at its melting point, is 63.7cal/g. Iron melts at 1530 C. How much heat must be added to 2g of iron at 25c to completely melt it?
March 15, 2013

Chemistry
How many moles of gas are in a 30 liter scuba canister if the tempature of the canister is 300 k and pressure is 200 atmospheres?
March 12, 2013

Chem
I have a balloon that can hold 100 liters of air. If i blow up this balloon with 3 moles of oxygen gas at a pressure of 1 atmosphere, what is them tempature of the balloon?
March 12, 2013

Chem
How many moles of gas are in a 30 liter scuba canister if the tempature of the canister is 300 k and pressure is 200 atmospheres?
March 12, 2013

Math
I think you may have misread the question. Check to see if .005x^2 is actually -.005x^2. Then follow the directions above. When you graph the flight of an object it should be a parabola that opens downwards. Think of the graph as a side view of the rock where the x-axis is the...
March 11, 2013

Math
A rock band has 5 members, and 2/5 of the members play string instruments. Also, 0.4 of the members sing. Does the band have the same number of string instrument players as singers. I think no. Am i correct? Please explain it.
March 6, 2013

Math
I mean it
March 6, 2013

Math
Thank you
March 6, 2013

Math
What's 6/20 in simplest form? ( I know what simplest form is)
March 6, 2013

Math
the number can be divided by a greater sum then.
March 6, 2013

Physics
A pitcher throws a baseball with a horizontal velocity of 132 ft/s (90 mph) toward home plate that is approximately 60 ft. away. What is the vertical drop of the ball when it reaches the plate? g = 32 ft/s^2.
February 26, 2013

Physics
A long jumper leaves the ground with an initial velocity of 12 m/s at an angle of 28-degrees above the horizontal. Determine the time of flight, the horizontal distance, and the peak height of the long-jumper.
February 26, 2013

Physics
Train A starts at 4 miles South of a bridge and heads North at a constant speed of 30 miles per hour. Train B starts 6 miles North of the bridge. a. What velocity must Train B have so that the two trains cross the bridge at the same time? b. If Train B goes at 35 miles per ...
February 26, 2013

Physics
A train is moving towards a destroyed bridge. The velocity of the train remains constant at 20 m/s. A person inside the train realizes that they will die unless they run to the back of the train and jump out. If the person is 15 m from the back of the train and the back of the...
February 26, 2013

Physics
At a certain instant, a ball is thrown downward with a velocity of 8.0 m/s from a height of 40 m. At the same instant, another ball is thrown upward from ground level directly in line with the first ball with a velocity of 12 m/s. Find (a) the time when the balls collide and (...
February 26, 2013

Physics
A plane is flying at 25 degrees north of west at 190km/ h. Suddenly there is a wind from 15degrees north of east at 45 km/ hr. what is the planes new velocity with respect to ground in standard position
February 22, 2013

Physics
Plane flying southwest at 155mi/hr. their is a wind from the west at 45.0mi/hr. what's the planes new velocity
February 21, 2013

MaTH
so is the perpendicular line is -2/3? What is the parallel line?
February 18, 2013

MaTH
Consider the line 9x-6y=-3 . What is the slope of a line parallel to this line? What is the slope of a line perpendicular to this line?
February 18, 2013

Mth
I suck in math as you can see and yes I will love more help
February 18, 2013

Math (Pre-Cal)
There is exactly one triangle the length of whose sides are integers in arithmetic progression and whose area is 156 square units. Find the perimeter of this triangle.
February 11, 2013

Math
An airplane approaches a runway at a 3 degree angle of depresssion. If the plane is flying at 30,000 ft., find the ground distance from the airport to the point directly below the plane when the pilot begins the descent. Round your answer to the nearest foot.
January 30, 2013

Math
An airplane approaches a runway at a 3 degree angle of depresssion. If the plane is flying at 30,000 ft., find the ground distance from the airport to the point directly below the plane when the pilot begins the descent. Round your answer to the nearest foot.
January 30, 2013

Biochemistry
Do you add Nacl or HCL if your target buffer pH is 8, and the buffer is HEPES
January 30, 2013

Physics
Two forces are applied to a car in an effort to move it, as shown in the following figure, where F1 = 433 N and F2 = 354 N. (Assume up and to the right as positive directions.) F1 is 10 degrees west of the y axis, F2 is 30 degrees east of the y axis. (a)What is the direction &...
January 30, 2013

Physics
Forces of 11.3N north, 19.1N east, and 14.5N south are simultaneously applied to a 4.12kg mass as it rests on an air table. What is the magnitude of its acceleration? What is the direction of the acceleration in degrees? (Take east to be 0 degrees and counterclockwise to be ...
January 26, 2013

Physics
A rowboat crosses a river with a velocity of 3.30 mi/h at an angle 62.5° north of west relative to the water. The river is 0.795 mi wide and carries an eastward current of 1.25 mi/h. How far upstream is the boat when it reaches the opposite shore?
January 25, 2013

MATH
THREE QUARTERS OF A POUND OF HONEY COSTS $4 HOW MUCH HONEY WOULD YOU GET FOR $6
January 23, 2013

Trigonometry
cos 17pi/6 + tan 17pi/6
January 23, 2013

Physics
compare the collision of a baseball and bat with the collision of a baseball and a fielder's glove when the baseball is caught. During which collision is there a greater momentum change for the baseball?
January 22, 2013

math
what is 0.0678/100
January 17, 2013

Physics
Question: particle J with zero initial mass and X energy accelerates from a static start to 'C' (light speed) in a time frame of N and mass increases 10 to the 28th power per nanosecond- -What is the mass on particle J? -What is the energy of particle J?
January 16, 2013

PLEASE HELP BIO
If the side chain of a glutamic acid residue has a pKa of 4.1, at pH 6.1 the ratio of uncharged to charged side chain would be about A. 100:1 B. 10:1 C. 1:1 D. 1:10 E. 1:100 -i HAVE NO IDEA Which of the following amino acids has a side chain that can serve ONLY as a hydrogen ...
January 16, 2013

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