Science & Mathematics - 21 August 2007

A landing craft is attempting to land on an unexplored planet in a distant solar system. As it nears the planet's surface, slowing down at a rate of 3.21 m/s2, its rocket engines provide an upward thrust force of 87.4 kN (kilonewtons). The craft's mass is 4480 kg. Calculate
(a) the local free-fall acceleration rate (g)
(b) the engine thrust that would be necessary for the craft to descend at a constant speed

2007-08-21 16:06:55 · 7 answers · asked by Anonymous in Physics

35. What is the concentration of the sodium ion, Na+ in a 0.300 M Na2CO3?
a)0.200 M
b) 0.300 M
c)0,600 M
d) 0.900 M

36. A 0.0010 M HCN solution has a ka = 6 x10^-10. Which terms describe this acid solution?
a)weak and dilute
b)strong and dilute
c)concentrated and weak
d) concentrated and strong

37. What is the ksp expression for strontium carbonate, SrCO3?

38. Ehat voume , in cm^3, of 0.100 M NaOH is required to beutralize 40.0 cm^3 of 0.100 M H2SO4?
a) 20.0
b) 40.0
c) 80.0
d)100

39. What must be true about this spontaneous reaction?
2Cr^2 + I2 > 2Cr^3 + 2I-
a) I2 is oxidized
b) Chromium ions are reduced
c) More electrons are lost than gained.
d) The standard potential is positive.

40. If 60 g of each solute is mixed with seperate 100 g sample of water at 20 C which forms unsaturated solutions?
a) all would be unsaturated.
b) only KBr would be unsaturated
c) only KNO3 would be unsaturated
d) NaCL, KCl, and KBr would be unsaturated

2007-08-21 16:02:04 · 1 answers · asked by sammy g 1 in Chemistry

Mercury , venus, earth revolve around the sun once every 3,7, and 12 months. If the three plantes are now inthe same straight line, what is the smallest number of the months thar must pass before they line up again

2007-08-21 16:01:32 · 4 answers · asked by Yolie b 1 in Astronomy & Space

This isn't a joke...um...do you have to pay a lot of money to have one built? I'm just wondering...

2007-08-21 16:00:08 · 6 answers · asked by Darkness.will.unleash.the.realm 2 in Earth Sciences & Geology

2007-08-21 15:58:47 · 7 answers · asked by blue15 1 in Mathematics

The alkaline earth metals have a +2 charge. What kind of charges do transition metals have?

2007-08-21 15:57:33 · 6 answers · asked by thunderbomb90 3 in Chemistry

Such as slugs and worms. I think it is wrong personally.

2007-08-21 15:57:13 · 4 answers · asked by Anonymous in Zoology

2007-08-21 15:56:12 · 6 answers · asked by Anonymous in Mathematics

please show me how

2007-08-21 15:55:40 · 6 answers · asked by Anonymous in Mathematics

Science investigates, examines, and classifies for the purpose of understanding things. But does it have some mission statement on what it's supposed to do with the info it discovers?

2007-08-21 15:55:33 · 7 answers · asked by Greywolf 6 in Other - Science

2007-08-21 15:54:53 · 5 answers · asked by Jenny R 2 in Zoology

I just need a small bottle for an experiment, so the cheaper the better.

2007-08-21 15:50:19 · 4 answers · asked by Soosha 1 in Chemistry

I have a DVD that discusses the future of the earth. But they mention the Andromeda Galaxy is headed toward us and could destroy our galaxy. The DVD producers also mentioned that the exterior of the sun is slowly growing and could eventually engulf us. But they also mentioned a major black hole "dragon" that is eating up galaxies and stars around us.

What will happen. Which is coming first? Which is more probable?

Thanks you great minds.

2007-08-21 15:48:04 · 7 answers · asked by J C 1 in Astronomy & Space

You are given a culture of an organism which is known to be Gram positive. You stain it by Gram's method and upon examination it appears to be red. What are the possible explanations for this?

I'd really appreciate the help! :p

2007-08-21 15:36:13 · 4 answers · asked by Hi, how are ya? 1 in Biology

2007-08-21 15:31:28 · 3 answers · asked by blue15 1 in Mathematics

Ok so i did like all these problems but i got ALL of them wrong. and my wrong answers make so much sence to me so i have no idea how there wrong. Could you please show the steps for these problms/exmplain. I have a terrible math teacher who doesnt teach anything. really frustrating

1. |4-x| - 10 = 1

2. |2x-5| = 3x + 4

3. |3x| -4 >8

4. |3x-6|+3<15

5. 7|8-3x| = 21x-49

6. 1/4|4x+7|= 8x+16

7. 1/11|2x-4| + 10<(greater then or equal too)11

2007-08-21 15:30:43 · 3 answers · asked by Anonymous in Mathematics

2007-08-21 15:29:52 · 4 answers · asked by Anonymous in Mathematics

I'm compiling a list of things various people want to learn from the JWST program. Scheduled to replace the aging Hubble in 2013, the James Webb Space Telescope will be able to look farther into space (and back in time) than ever before.

What discoveries will be made? What phenomena will be revealed? How will this alter our views of our galaxy and universe? Will it solve any mysteries of space, time or religion? What are the implications for future space exploration? What would YOU like to know?

2007-08-21 15:28:54 · 4 answers · asked by therollingrock 1 in Astronomy & Space

An average school bus holds 45 people. Sketch a graph showing the relationship between the number of students who need bus transportation and the number of buses required. Be sure to label the axis.

2007-08-21 15:28:03 · 3 answers · asked by Nicole 5 in Mathematics

Lets say my dad is 5'7, however, he is that short because when he was younger he was exposed to malnutrition, stressing hard work and very little time to sleep. So here are my questions:

1. Will i inherit his height which is 5'7 or would i inherit a height higher than 5'7 because of his conditions when he was younger?

2007-08-21 15:26:46 · 3 answers · asked by Anonymous in Medicine

Juan loves making home improvements. His next project is his backyard. He wants to place a 2ft wide marble walkway around his pool. The rectangular pool measures 15ft wide and 20ft long.

Draw a diagram of Juan's pool and walkway. (Label the dimensions)

Find the area of the walkway that surrounds the pool.

Juan found a good sale at Marble World. The marble that he wants to place around his pool costs $25 per square foot. How much will Juan spend on the marble to make the walkway around his pool? (Round to the naerest hundredth)

2007-08-21 15:25:01 · 6 answers · asked by angel 1 in Mathematics

cause alot of people beleive in that stuff.

2007-08-21 15:24:54 · 7 answers · asked by Anonymous in Physics

2z-5(z+2)=-8-2z

also

5t-2(5+4t)=3+t-8

2007-08-21 15:23:44 · 3 answers · asked by LEE 1 in Mathematics

2007-08-21 15:13:49 · 4 answers · asked by Eddie F 1 in Zoology

please and thanks! :]

while your at it, what is the speed of sound in mph and kph?

2007-08-21 15:12:36 · 3 answers · asked by Heatherfacee:] 1 in Astronomy & Space

12 20 35

2007-08-21 15:05:19 · 4 answers · asked by rudyspuddin 4 in Mathematics

2007-08-21 15:04:15 · 4 answers · asked by alan82nd 1 in Biology

Please provide a link to read more about it, if any.

2007-08-21 15:04:11 · 3 answers · asked by jeet 1 in Other - Science

2007-08-21 14:55:09 · 7 answers · asked by jetman22003 1 in Engineering

2007-08-21 14:54:27 · 4 answers · asked by Anonymous in Medicine