Saturday

February 25, 2017
Total # Posts: 199

**Physics**

If a ball is launched straight upwards from the ground with an initial velocity of 20.0 m/s, how long does the ball take to reach a height of 15.0 m on the way up? For the same situation, at what time does the ball reach 15.0 m on the way back down?

*September 18, 2016*

**physics**

A diffraction grating with 1000 slits/cm is oriented parallel to the y-axis and its center is located on the x-axis at x = -5.00 m. A source of light of wavelength 650 nm is located on the x-axis at x = -125 m. At how many locations does constructive interference occur on the ...

*May 25, 2016*

**Chemistry**

If 125 grams of KClO3 decomposes completely, how many moles of oxygen gas is produced?

*April 28, 2016*

**Science**

A constant volume of O2 gas is heated from 140C to 216C. The final pressure is 22.3 atm. What was the initial pressure?

*April 13, 2016*

**Physics**

How high would you have to lift a 0.294N mouse to do the same amount of work that you would do if you lift a 6.87 kN elephant 1.00cm?

*April 11, 2016*

**programming**

yes I would like to be programming right no

*February 18, 2016*

**radicals**

(sqr8) {(sqr9ab)/(sqr3b) + (sqr27a)} How do you solve this

*February 7, 2016*

**Math Radicals**

(2√5+3)(2√5+3)= a + b√c+d Figure out the binomial to find a,b,c,d

*February 6, 2016*

**Physical science**

the space shuttle typically orbits 400 km above the earth's surface.the earth hass a mass of 5.98*10 to the 24 squared kg and a raduis of 6,380 km.A)how much would a 2000 kg part form the space station weight when it has been lifted to that orbit in the shuttle's cargo...

*December 7, 2015*

**Math**

Lisa ate 1/3 of pizza. Kate ate 4/12 of same pizza. What fraction did they eat altogether

*December 1, 2015*

**Math**

Put these fractions in order from least to greatest.2/5 3/4 and 1/2. I am trying to help my daughter with her homework. Would you please explain to me how the easiest way to do this.

*November 10, 2015*

**algebra**

suppose you have 60$ ro buy a shrimp and chicken wings for a party. shrimp costs $10/lb and wings cost$6/lb. write a linear equation that could be used to determone the number of pounds of each food that can be purchased with 60$

*November 10, 2015*

**Calculus**

An automobile depreciates by 23% per year. How soon will it be worth only half its original value?

*October 12, 2015*

**chemistry**

1. A

*July 10, 2015*

**physics**

A solid uniform cylinder of mass 4.6 kg and radius 0.051 m rolls without slipping at a speed of 0.78 m/s. What is the cylinder’s total kinetic energy? please show some work so that I can learn from it.

*June 29, 2015*

**physics**

A child pushes a merry-go-round with a force of 80.0 N at an angle tangent to the circle (that is, perpendicular to a radius). If the child pushes it through exactly one full circle, and the merry-go-round has a radius of 1.15 m, how much work does she do? If you could please ...

*June 29, 2015*

**Algebra**

Solve using the substitution method. -5x + y = 16 9x + 13y = 60

*June 29, 2015*

**Algebra**

One canned juice drink is 15% orange juice another is 5% orange juice. How many liters of each should be mixed together in order to get 10L that is 12% orange juice?

*June 29, 2015*

**Algebra**

A store mixes red fescue worth $10 per pound and ryegrass worth $13 per pound. The mixture is to sell for $12 per pound. Find how much of each should be used to make a 120 pound mixture.

*June 29, 2015*

**Algebra**

In 2009, a diabetic express company charged $39.95 for a vial of type A insulin and $30.34 for a vial of type B insulin. If a total of $1747.64 was collected for 50 vials of insulin, how many vials of each type were sold?

*June 29, 2015*

**English, Written Communication**

the answer is d I just took the test

*May 22, 2015*

**chemistry**

A 8.60-g sample of solid CaSO4·2H2O was heated such that the water turned to steam and was driven off. Assuming ideal behavior, what volume would that steam occupy at 1.00 atm and 100.0 °C?

*March 18, 2015*

**Physics**

a siren has a frequency of 1099 Hz when it and an observer are both at rest. The observer then starts to move and finds that the frequency he hears is 1185 Hz. What is the speed of the observer?

*March 6, 2015*

**Physics**

The driver of a car slams on the brakes when he sees a tree blocking the road. The car slows uniformly with acceleration -5.40 m/s2 for 4.40 s, making straight skid marks 63.1 m long ending at the tree. With what speed does the car then strike the tree?

*January 22, 2015*

**Math**

Madeline had a class ratio of 5:4 boys to girls in her classroom. If there were 27 kids in her class how many girls were there?

*November 10, 2014*

**Math**

Diane took a math test. The ratio of the number of problems Diane got incorrect to the number of problems she got correct was 2:7. If the test had 36 questions on it, how many problems did she get correct?

*November 10, 2014*

**Chemistry**

An electrical heater is used to supply 200.0 J of energy to a 30.0 g sample of water, originally at 285.0 K. Determine the final temperature in degrees Kelvin. (the specific heat capacity for water is 75.291 Jmol-1K-1)

*October 21, 2014*

**Chemistry**

Why 22.4?

*October 21, 2014*

**Chemistry**

for that reaction and its kj

*October 21, 2014*

**biology**

Where is the location of the phosphatase enzyme in the digestive system. There is no site that i can find that can provide an answer...

*October 19, 2014*

**physics**

A block of mass m is pushed along a horizontal table by a force F= 70 N a an angle 55 degrees with the horizontal. The coefficient of kinetic friction is 0.3 Write Newtons second law using vectors. Write newtons second law using x scalar components

*October 17, 2014*

**Chem**

hey ;)

*September 28, 2014*

**Chemistry**

PLEASE help because I'm really confused on how to do the entire thing. I don't know how to find the mL. Am I suppose to do anything with the 250mL? A person stops in every day and orders 250 mL of house coffee at precisely 95°C. but enough milk at 10°C to drop ...

*September 25, 2014*

**math**

How would I go about dividing. -20 divided by (-2 1/2)

*September 21, 2014*

**Math**

167.53

*September 10, 2014*

**CHEM 1A**

Sweet. Thank you. I was real close. I was just calc ing the moles wrong at the end. Thanks again

*September 6, 2014*

**CHEM 1A**

Can someone please help me..... I have limited reactant formula problem. I am completely lost. 2Ca(s) + O2(g) ----> 2CaO(s) Calculate the mass of Calcium Oxide that can be prepared from 6.87g of Ca and 4.58g of O2. I calculated 2Ca to .171mol and O2 to .286mol, I am lost ...

*September 6, 2014*

**6th grade math**

Think about your number line starting at 0 from left to right. Negative numbers are always less than positive. Integers are numbers, whole numbers. you know least to greatest on your positive, right? Negative numbers are just reversed....

*September 5, 2014*

**CHEM 1A**

Sweet, Thank you....

*September 5, 2014*

**CHEM 1A**

Balanced equation, 4KNO3(s) ----->2K2O(s) + 2N2(g) + 5O2(g) To produce 51.8kg of O2, How many moles of KNO3 must be heated? How many grams of KNO3 must be heated? Do you calculate like KNO3 and O2 is just one mole or do you divide 4/5 at the end of the equation? 51.8kgO2 x ...

*September 5, 2014*

**7th grade Math**

There are 50 questions on a test. If a 60% is considered passing, how many questions do you have to get right to pass?

*October 29, 2013*

**Mathematics**

Is 27.38452... a real and a rational number?

*October 22, 2013*

**Math**

How do you write the number 339.4 X 10 -10 in scientific notation?

*August 27, 2013*

**Math**

If the length and width of a triangle are tripled, what is the effect on the area?

*August 27, 2013*

**Math**

Which expression represents the number in the pattern where "p" is the position of the number in the pattern? 20, 24, 28, 32, 36 a. 4(p +3) b. 4p - 4 c. 4p + 4 d. 4 (p+4)

*August 27, 2013*

**Physics**

A ball with a mass of 0.25 kilogram is swung on the end of a rope that is 3.0 meters long. The ball travels with a linear velocity of 10.00 meters per second. What centripetal force is acting on the ball?

*May 29, 2013*

**Chemistry**

A gas occupies 275 ml at 0°C and 610 Torr. What final temperature would be required to increase the pressure to 760 Torr, the volume being held constant?

*May 2, 2013*

**physics**

Bill has a mass of 83.6 kg. Jane has a mass of 51.0 kg. If they are seated 4.3 m apart, how much gravitational force attracts them?

*April 23, 2013*

**Chemistry**

A marathon runner will burn 1.25x10^7 j during a race. If the calorie content of 12.0 oz. of Gatorade is 80.0 kilocalories, how many ounces of Gatorade must the runner drink to provide enough energy for the race? Note: 1 Calorie=4.184j and "kilo"= 10^3

*April 20, 2013*

**Chemistry**

An alloy contains 39.5 mass% silver (Ag) and has density og 7.86 g/ml What volume of alloy would be needed to contain 12.0g of pure Ag?

*April 20, 2013*

**Chemistry**

A student uses 57.4 ml of 0.2m of RbOH to titrate 25.0ml of HcLo3. What is the concentration of HcLo3?

*April 18, 2013*

**physics**

Just wanted to say a quick thanks to Steve and Damon, figured it all out, thanks guys, awsome!!!

*April 12, 2013*

**physics**

I gave the wrong answer at first. Sorry.

*April 12, 2013*

**physics**

Sorry the answer they have is 60.5 degrees east of of north or 29.5 degrees north of east. There would be two vectors right, so do you take the degrees from the resultant? Thanks Damon, I do not nothing about this stuff at all. The question says my answer should be found by ...

*April 12, 2013*

**physics**

A boat is traveling on a bearing of 25 degrees East of North at a speed of 4 knots (a knot is 1.852 km/h). After traveling for 3 hours, the boats heading is changed to due South and it travels for an additional 2 hours at 5 knots. Using a Vector diagram, what is the resultant...

*April 12, 2013*

**physics**

Sorry Steve wrong answer, they got 60.5 degrees east of north or 29.5 degrees north of east. Sorry about that.

*April 11, 2013*

**physics**

Hi Steve, thank you. The answer for the question 81.4N at 84 degrees west of north or 6 degrees north of west. But they show no work to get the answer. I am still confused, please help me a little more. Thanks Steve.

*April 11, 2013*

**physics**

A boat is traveling on a bearing of 25 degrees East of North at a speed of 4 knots (a knot is 1.852 km/h). After traveling for 3 hours, the boats heading is changed to due South and it travels for an additional 2 hours at 5 knots. Using a Vector diagram, what is the resultant...

*April 11, 2013*

**physics**

A boat is traveling on a bearing of 25 degrees East of North at a speed of 4 knots (a knot is 1.852 km/h). After traveling for 3 hours, the boats heading is changed to due South and it travels for an additional 2 hours at 5 knots. Using a Vector diagram, what is the resultant...

*April 10, 2013*

**physics**

Hi, I am completely new to this, and missed a lot of classes due to hospital trips. Trying to cathc up but there is no sample question in my text. I don't really know how to get the numbers to make the vectors. Can you lead me in the right direction, would be very much ...

*April 7, 2013*

**physics**

A boat is traveling on a bearing of 25 degrees East of North at a speed of 4 knots (a knot is 1.852 km/h). After traveling for 3 hours, the boats heading is changed to due South and it travels for an additional 2 hours at 5 knots. Using a Vector diagram, what is the resultant?

*April 7, 2013*

**physics**

A boat is traveling on a bearing of 25 degrees East of North at a speed of 4 knots (a knot is 1.852 km/h). After traveling for 3 hours, the boats heading is changed to due South and it travels for an additional 2 hours at 5 knots. Using a Vector diagram, what is the resultant?

*April 6, 2013*

**physics**

A boat is traveling on a bearing of 25 degrees East of North at a speed of 4 knots (a knot is 1.852 km/h). After traveling for 3 hours, the boats heading is changed to due South and it travels for an additional 2 hours at 5 knots. Using a Vector diagram, what is the resultant?

*April 5, 2013*

**Physics**

I am trying to help my step son who missed half of physics class due to a funeral. A laser beam is being shot through two different materials that have been stuck together. if theta 1 = 65.5 and theta 2 = 49.8 what is the index of refraction? (I got 1.2 which is correct) but ...

*April 4, 2013*

**science**

: how much work is done by 0.020 meters squared of gas if its pressure increases by 2.0 multiplied by 10 to the 5th power Pa and the volume remains constant ?

*February 27, 2013*

**Physics**

A rowboat passenger uses an oar to push the boat off the dock by exerting a force of 40.0 N for 3.0 s. What impulse acts on the boat? What formula do I use?

*February 16, 2013*

**Math**

Mrs coopers 5th grade class has 11 more girls than boys. There are 35 students in all. How many girls are there?

*January 24, 2013*

**math**

what amount of principal would yield an interest of $36 in 3 years at a 3% simple interest rate?

*January 24, 2013*

**Science: Physics**

A force of 50 N directed at an angle of 45 degrees from the horizontal pulls a 70 kg sled across a frictionless pond. The acceleration of the sled is most nearly (sin 45 degrees = cos 45 degrees = 0.7).

*December 1, 2012*

**physics**

what is the frequency of wavelength 5.5cm travelling at 2 a speed of 1.6 m\s?

*November 19, 2012*

**physics**

A class of 11 students taking an exam has a power output per student of 122 W. Assume that the initial temperature of the room is 18.8oC and that its dimensions are 6.40 m by 14.5 m by 3.50 m. What is the temperature of the room at the end of 54.0 min if all the heat remains ...

*November 10, 2012*

**Chemistry**

Tell how to synthesize each compound. A. Ni(OH)2 B. MgSO4 C. KNO3

*October 26, 2012*

**physcis**

a flight attendant pulls her 70 kg flight bag in an airport terminal holding the handle 50 degrees above the horizontal. she pulls the bag a distance of 200 m while exerting a 40 n force acting along the handle with a constant speed how much work does the flight attendant ...

*October 20, 2012*

**Algebra**

The length of a rectangle is 5 less than twice the width. Find the dimensions if the perimeter is 110?

*October 15, 2012*

**Physics**

When you see a traffic light turn red, you apply the brakes until you come to a stop. Suppose your initial speed was 12.9 m/s, and you come to rest in 35.0 m. How much time does this take? Assume constant deceleration. What equation do I use to solve this problem? You can show...

*October 4, 2012*

**math**

90 volts are applied to a circuit with 3 resistors resistor 1=20 ohms resistor 2=40 ohms and resistor 3=60 ohms how much power will be dissipated by resistor 1

*September 19, 2012*

**Chemistry**

How many moles of H_2 are needed to produce 13.27g of NH_3?

*September 19, 2012*

**Physics**

Two identical masses are connected by a (massless, stretchless) string across a (massless, frictionless) pulley. The mass on the right is held so that the string connected to it is horizontal. Everything is initially at rest; the tension is the string is zero. The mass on the ...

*August 10, 2012*

**Physics**

Bob, AKA smart guy, I already figured it out thank you very much. You obviously didn't read the question as it says don't use derived equations from the textbook. Wouldn't you assume conservation of energy and momentum equations are in the book?

*August 10, 2012*

**Physics**

A low friction cart of mass m, traveling at speed v, collides (perfectly) elastically with a cart of triple the mass, initially at rest. What is the result of this collision? (What are the final, after-collision velocities?) Do NOT use the derived equations from the textbook. ...

*August 10, 2012*

**Physics**

A flatbed truck with a box sitting on the bed accelerates from rest on level ground. The truck’s speed as a function of time is 15t –2t^2 during this acceleration. The truck reaches its maximum speed and cruises along at this speed for 4 minutes. It then slows to a ...

*August 10, 2012*

**Physics**

A 750 kg car traveling 22.0 m/s due north crashes into a 1500 kg truck traveling 20 m/s due west. The two vehicles become locked together and travel 19.0 m before stopping. Find the average frictional force (magnitude and direction) that brings the two to a stop.

*August 10, 2012*

**Physics**

The wind blows a 0.50 kg Styrofoam box, initially at rest, across level ground and then up an incline where it comes to a rest. The box slides 6.0 m on level ground before sliding up the 20.0 Ovincline. If the effective coefficient of friction between the ground and the box ...

*August 9, 2012*

**Physics**

Some object moves 220.0 m at an angle of 42° north of west. During this motion, a 68.0 N force acts on the same object, doing +5460.0 J of work on the object. Assuming the force is applied horizontal to ground, what is this force’s orientation? Is there more than one ...

*August 9, 2012*

**Physics**

A block of mass m has a spring –spring constant k and length L –connected, vertically, to the bottom. The block is dropped from height h, towards the floor. Assuming the spring is stiff enough that it does not compress fully at the floor, what is the closest distance...

*August 9, 2012*

**Physics**

Box, mass m 1 , at rest against a compressed spring, spring constant k and compression of Δx, at the top of a ramp, height h, is released. It slides down the ramp, angle θ, with friction, coefficient μ. Half way down the ramp, it bumps into and sticks to another...

*August 9, 2012*

**Physics**

Jenn Suhr recently won the gold medal in this summer’s Olympic games in pole vault. Her record is 16 ft, 2 in. (She did less than that to win gold this summer.) If all of her gravitational potential energy came only from her kinetic energy, calculate (in m/s) the running ...

*August 8, 2012*

**Physics**

In the school cafeteria, a trouble-making child blows a 12.0 g spitball through a 25.0 cm straw. The force of her breath as a function of the distance along the length of the straw can be modeled as 10-50x^2-70x^3 where force is in newtons and x is in meters. (a) How much work...

*August 8, 2012*

**Physics**

A missile launcher, mass M, at rest on a horizontal track fires a missile, mass m, horizontally. a) If the launch speed of the missile is v o , what (effective) coefficient of (kinetic) friction is required in order to stop the launcher within x meters? (b) Missile launcher ...

*August 8, 2012*

**Physics**

A missile launcher, mass M, at rest on a horizontal track fires a missile, mass m, horizontally. a) If the launch speed of the missile is v o , what (effective) coefficient of (kinetic) friction is required in order to stop the launcher within x meters? (b) Missile launcher ...

*August 7, 2012*

**Physics**

A cart is coasting at a speed v A along a straight and level road. When ten percent of the wagon’s mass is thrown off the wagon, parallel to the ground, and in the forward direction, the wagon stops. However, if this same amount of mass is thrown out the back of the wagon...

*August 7, 2012*

**Physics**

A 5.0 kg shell is fired vertically upward. At its max height of 350.0 m, it explodes into 3 pieces. A 1.0 kg chunk lands 15.0 m away, 45 O due northeast from the launch site. A second 1.0 kg piece lands 25.0 m, 60 O south of east from the launch site. If all 3 pieces land at ...

*August 7, 2012*

**Physics**

A 140 g, 90.0 mph fastball comes across the plate very nearly horizontally and is batted at 90.0 mph at a 30.0O angle (above the horizontal) toward center field. (a) Determine the impulse (in N.s) acting on the ball. (b) If the impact time is 0.00080 s, determine the average ...

*August 7, 2012*

**Physics**

A 140 g, 90.0 mph fastball comes across the plate very nearly horizontally and is batted at 90.0 mph at a 30.0O angle (above the horizontal) toward center field. (a) Determine the impulse (in N.s) acting on the ball. (b) If the impact time is 0.00080 s, determine the average ...

*August 6, 2012*

**Physics**

A 125 kg flatbottomed boat is floating along at 5.0 m/s, headed east. Sally Sue, standing at one end of the boat, starts to walk at 2.0 m/s, also to the east. If Sally’s mass is 65 kg, what is the speed of the boat as she walks along?

*August 6, 2012*

**Physics**

A car, starting from rest, accelerates down a hill reaching 30.0 m/s in 6.00 s. During this time, the driver notices that the fuzzy dice hanging by a string from the ceiling is perpendicular to the ceiling. Find (a) the angle θ of the hill and (b) the tension in the string.

*July 24, 2012*

**Physics**

The weight of an object is the same on two different planets. The mass of planet A is sixty percent that of planet B. Find the ratio of the radii of the two planets, rA/rB

*July 24, 2012*

**Physics**

A box starting from rest, slides down an incline which makes an angle of θ above the horizontal. The incline has a maximum height of h above the platform on which it sits which is itself H above the ground. The box leaves the end of the ramp and platform's edge and ...

*July 24, 2012*

**Physics**

A 565 N mountain climber moves across a rope strung across a canyon. When she is more than halfway across, she notices the rope makes a 10 degree angle (from horizontal) behind her and a 25 degree angle (from horizontal) ahead of her. What are the tensions in the rope in front...

*July 24, 2012*