# Posts by Bob

Total # Posts: 3,273

**Science**

Which source is not a source for fossil fuels? coal mine ancient swamps ancient living organisms corn fields

**Science**

What uses wind to generate electricity?

**Science**

Can you explain it?

**Science**

Different kinds of sedimentary rocks exist because A. they were formed in different places B. their formation took different lengths of time C. they were formed by sediments from different rocks D. they have been cut differently I THINK ITS C is that right?

**geometry**

Question 14: The following circle has a radius of 8 feet: What is the total area of the shaded regions?

**calculus**

I hate calculus

**statistics**

A density graph for all the possible speeds between 0 mph and 320 mph is in the shape of a triangle. What is the height of the triangle?

**Chem!!**

Consider the dissolution of CaCl2: CaCl2(s) -----------> Ca2+(aq) + 2Cl-(aq) ΔH=-81.5 kJ/mol An 11.0 gram sample of CaCl2 is dissolved in 125 g water with both substances at 25.0 °C. Calculate the final temperature of the solution assuming the solution has no heat ...

**Science**

What is the source of energy in fossil fuels?

**PREDICT**

In 1955 each farm worker in the United States produced enough food to feed 20 people. By 1960 farming methods had improved, and one worker could supply 25 people. By 1965 that number became 40 people. In 1970 it was 45 people.In 1975 it increased to 60 people. In 1980 one ...

**Predict**

In 1955 each farm worker in the United States produced enough food to feed 20 people. By 1960 farming methods had improved, and one worker could supply 25 people. By 1965 that number became 40 people. In 1970 it was 45 people.In 1975 it increased to 60 people. In 1980 one farm...

**Physics**

24.7

**Math Logic**

If there are as many rational numbers as there are irrational numbers then the set of all irrational numbers is infinite

**statistics**

so you look like mixed toast ha ha

**Math**

Which group names all the whole number factors of a composite number? A) 2,3,12,24 B) 1,5,10 C) 1,3,5,15 D) 1,31

**Math**

How high will a baseball that is thrown up into the air at 48 feet per second go if it starts its flight at a height 10 feet above the ground?

**Language**

It is b because a platypus is a platyhhelminthes, and a worm is a marsupial

**Math**

k thanks

**Math**

what does 4 _____ 6 equal

**Math**

what does 4 - 6 equal?

**Physics**

what is g

**Algebra**

R=(500-25x)(2+0.25x)

**chemistry**

If 25 ml of 0.11 M sucrose is added to 10 ml of 0.52 M sucrose, what will be the resulting Molarity?

**physics**

a small bead can slide without friction on a circular hoop that is in a vertical plane and has a radius of 0.100 m. The hoop rotates at a constant rate of 3.00 rev/s about a vertical diameter. Find the angle beta at which the bead is in vertical equilibrium. what would happen ...

**Science**

Which process takes the longest time? A) The wind erodes a sand dune on the beach B) A maple tree grows to be 100 feet tall C) High mountains are eroded to gentle hills D) A river floods and changes its course

**Science**

Which of the following describes the slowest change on earth's surface? A) Gravity pulls an area of wet soil and rock downward in a landslide B) An earthquake releases energy that built up below Earth's surface C) Lava explodes from a volcano on an island D) A canyon ...

**Physics**

Work of 730 J is done by stirring an insulated beaker containing 80 g of water. What is the change in the temperature of the water? Please show calculation

**......**

Why do some people delete other messages

**physics**

A hockey puck slides across the ice at a con- stant speed. Which of the following is true? 1. The puck is moving and thus not in equi- librium. 2. The puck can be considered neither at rest nor in equilibrium. 3. It is in equilibrium. 4. None of these 5. The puck is at rest.

**science**

how do cells use food using big idea of energy

**science**

how do cells use food using big idea of energy

**chemistry**

The solubility product constant (Ksp) for the dissolution of Cu(OH)2 as represented by the chemical equation is 2.6 x 10-19. Cu(OH)2 (s) Cu2+ (aq) + 2 OH- (aq) Calculate the moles of Cu(OH)2 that dissolves in 1900 mL of water. i know how to do it when its one to one but for ...

**art**

got a project about you need to find 12 pictures to suit the vales like line texture and etc

**physics**

42

**Algebra**

I have 37 coins, nickels dimes, quarters that equal 5.50 . I have 4 more quarters than dimes . How many nickels do I have?

**Organic Chemistry**

What is the mechanism of action between sodium benzoate (NaC6H5COO) and hydrochloric acid (HCl)? I need to know where the electrons go in this reaction.

**Organic Chemistry**

What is the mechanism of action between between benzoic acid (C6H5COOH) and sodium bicarbonate (NaHCO3)? I need to know where the electrons go in the acid-base reaction.

**Engineering Statistics**

what numbers did u plug in for z and x in the formula z=x-u divided by the s.d

**statistics**

A sample of 12 measurements has a mean of 20 and a standard deviation of 2. Suppose that the sample is enlarged to 14 measurements, by including two additional measurements having a common value of 20 each. Find the standard deviation of the sample of 14 measurements.

**Math**

1.8=[(5.0-x)/100]/[x/150] Solve for x

**calculus**

t(t-4)(t-4)

**Chemistry**

You have a solution that contains 5.0 grams of oxalic acid dissolved in 150 mL of water. This solution is placed in a separatory funnel, and the 100 mL of diethyl ether is added to the separatory funnel and an extraction is performed. Use the following constants to calculate ...

**Chemistry**

You have a solution that contains 5.0 grams of oxalic acid dissolved in 150 mL of water. This solution is placed in a seqparatory funnel, and the 100 mL of diethyl ether is added to the separatory funnel and an extraction is performed. Use the following constants to calculate ...

**chemistry**

On an activity series for metals aluminum is more active than hydrogen. Write the correct reaction to describe putting a piece of aluminum foil (pure aluminum) in 100 mL of hydrochloric acid

**social studies**

You can go to google

**physics**

An 8.4 g bullet is accelerated in a rifle barrel 45 cm long to a speed of 1020 m/s. Use the work-energy theorem to find the average force exerted on the bullet while it is being accelerated.

**geometry**

I really do not know, you have all the information I have in a math question

**geometry**

I have 4 pairs of parallel sides and each angle is 45 degrees, what am I

**Physics**

Show that there is no Brewster’s angle for s polarization.

**Physics**

Show that there is no Brewster’s angle for s polarization.

**calculus**

A mass on a spring vibrates horizontally on a smooth level surface. Its equation of motion is x(t)=8sint, where t is in seconds and x in centimeter. a. Find the velocity and acceleration at time t b. Find the position, velocity, and acceleration of the mass at time t=2pi/3. In...

**calculus**

Find the points on the curve y=(cosx)/(2+sinx) at which the tangent is horizontal.

**Physics**

Show that there is no Brewster’s angle for s polarization.

**Physics**

After the Sun exhausts its nuclear fuel, its ultimate fate may be to collapse into a white dwarf state. In this state, it would have approximately the same mass as it has now, but its radius would be equal to the radius of earth. (a) Calculate the average density of the white ...

**physics**

A hot air balloon is going up ward at a constant speed of 3.5 m/s. When it is 78 m above the ground, a package is released from the balloon. After it is released, for how long is the package in the air? The acceleration of gravity is 9.8 m/s2 . Answer in units of s

**math**

solve for b ab+3c=2x, I got b=2x-3c/a

**chem**

If the initial pressure of HD(g) is 2.270 atm, calculate the % decomposition of HD(g) when the reaction comes to equilibrium according to the balanced equation. The value of Kp at 727.0 °C is 0.26. The initial pressure of the reaction products is 0 atm. 2HD(g) = H2(g)+D2(g)

**physics**

A rocket-powered hockey puck has a thrust of 2.20 and a total mass of 0.700 . It is released from rest on a frictionless table, 2.90 from the edge of a 2.80 drop. The front of the rocket is pointed directly toward the edge.

**chemistry**

The initial concentration for the compounds involved in the reaction displayed were determined to be [CH4(g)] = 0.9530 mol/L, [H2O(g)] = 0.9911 mol/L, [CO(g)] = 0.7474 mol/L, [H2(g)] = 0.2717 mol/L. Calculate the value of the equilibrium constant (Kc) at 1200 K if the ...

**chemistry**

Calculate the molarity (M) of Na+ in a solution prepared by adding 1.00 L of 0.800 M NaHC2O4 and 250 mL of 0.300 M NaHC2O4 . Assume volumes are additive. the answer is 0.700 but im not sure how to go about solving it please help thanks

**U.S. History**

Thanks

**U.S. History**

What is the Sullivan Act?? and was it of 1911 or 1924??

**Math**

3 ^ (y+7) = 8 find y..i know you have to change 3 & 8 to the same thing so you can cancel them out and bring the exponents down but i don't know what you have to multiply it by.

**Chemistry**

The speed of light is = 3x10^8 m/s. How long w ill it take to reach Pluto, 278,000,000,000 km away? This is how I solved it: 3x10^8m/s x 1km/1000m x 1/2.78x10^11 km I keep getting the wrong answer. I am not sure if this is how you set this conversion??

**Chemistry**

So how would i get 100.625 nm/Msec?

**Chemistry**

A dragster moves at a speed of 225 miles per hour. Express this speed in nanometers per Microsecond. Ok so I've solved this problem like twenty times, each time adding something into the equation or taking something out and I almost got the correct answer, but I was three ...

**Chemistry**

Thank You So Much

**Chemistry**

length in cm of one side of perfect cube of gold with a density of 18g/cc and mass of 25g? How would i set up this equation? I don't know what length formula I would use, because I know that i am not supposed to just divide the density by the mass, because that would be ...

**Science/math**

2.72 hours

**Chemistry**

so would it be 3x10^8mi/1sec x 1000km/1m x 60sec/1 min x 60min/1hr x and then what??

**Chemistry**

The speed of light is = 3x10^8 m/sec. How long will it take to reach Pluto, 278,000,000,000 km away? I don't understand how to set this problem?

**Chemistry**

I am unsure if it starts like 3x10^8m/1sec

**Chemistry**

The speed of light is = 3x10^8 m/sec. How long will it take to reach Pluto, 278,000,000,000 km away? I don't understand how to set this problem?

**geometry**

<DOE contains points D(2,3) O(0,0) and E(5,1). Find the coordinates of a point F so that OF is a side of an angle that is adjacent and supplementary to <DOE

**geometry**

<DOE contains points D(2,3) O(0,0) and E(5,1). Find the coordinates of a point F so that OF is a side of an angle that is adjacent and supplementary to <DOE

**Science**

Lindana

**Calculus**

Use interval notation to indicate where f(x) is continuous. f(x)= 7x^8-5x^4+4

**Science**

If an object has a volume of 22 liters and a mass of 35 kilograms what's the objects density?

**Science**

If an object has a volume of 22 liters and a mass of 35 kilograms what's the objects density?

**Science**

If an object has a volume of 22 liters and a mass of 35 kilograms what's the objects density?

**Business Math**

Joyce took out a loan for $21,900 at 12 percent on March 18, 2007, which will be due on January 9, 2008. Using ordinary interest, Joyce will pay back on Jan. 9 a total amount:

**math**

the diagram shows a trapeze in a childrens playground. AC is horizontal bar 1.2m long. BX and DY are vertial posts each 3.4m tall. they are 2.5m apart. AC is suspended by ropes, AB and CD each 2.0m long. Calculate to one decimal place the vertical height of AC above the ground

**physics**

a car slows from 22m/s to 3m/s at a constant rate if 2.1m/s. how many seconds are required before the car is traveling at 3m/s

**algebra**

Mike drove 80 miles per hour. How long will it take Mona to drive 100 miles.

**spanish**

ustedes Nosotros

**math**

trying to find out the 7 numbers to a data set with The minimum 17 The range is 45 The median is 32 The mode is 41

**math**

trying to find out the 7 numbers to a data set with The minimum 17 The range is 45 The median is 32 The mode is 41

**chem**

0.015

**physics**

A skateboarder, starting from rest, rolls down a 13.9-m ramp. When she arrives at the bottom of the ramp her speed is 6.06 m/s. (a) Determine the magnitude of her acceleration, assumed to be constant. (b) If the ramp is inclined at 33.2 ° with respect to the ground, what ...

**algebra**

10 = X/4 -8 X OVER FOUR IS A FRACTION

**algebra**

4b + 6 = -2

**math riddles for 7th grade**

trying to find a porking place

**MATH**

25 METERS IS EQUAL TO HOW MANY GIGAMETERS

**math**

Woops. I accidentally wrote .09 instead of .907 However, the actual answer is just the result of the distance divided by the rate (aka whatever 39/43 is).

**math**

Distance = rate * time 39 miles is the "Distance" from Franklin to his home, and 43 m/hr is his "rate" of travel. You are trying to figure out the "time" it takes for him to get home traveling at this "Distance" and "rate". ...

**Physics**

yes

**Social Studies**

nothing helps me

**geography**

it is day

**physics**

A skateboarder shoots off a ramp with a velocity of 6.8 m/s, directed at an angle of 56° above the horizontal. The end of the ramp is 1.5 m above the ground. Let the x axis be parallel to the ground, the +y direction be vertically upward, and take as the origin the point ...