Branches of Science
Recent Science Questions
In the construction of bridges and skyscrapers, gaps must be left between adjoining steel beams to allow for the expansion and contraction of the metal due to heating and cooling. The temperature of a sample of iron with a mass of 10.0g changed from 50.4oC to 25.0oC with the ...
Sunday, July 6, 2014 at 10:25pm
An object with mass 110 kg moved in outer space. When it was at location < 11, -35, -7 > its speed was 17.5 m/s. A single constant force < 230, 420, -230 > N acted on the object while the object moved to location < 16, -41, -13 > m. What is the speed of the ...
Sunday, July 6, 2014 at 2:31pm
Do houseplants affect the quality of air in a house? Describe an experiment that would answer this question. What gases do you want to measure? I answered yes since plants give off oxygen which animals need to survive. I need a little help with the experiment.
Friday, July 4, 2014 at 5:21pm
What happens when mineral deposits are found? A. Miners lose their jobs. B. Mining towns are started. C. Nearby water supplies dry up. D. People move away from the deposits. My answer- C
Thursday, July 3, 2014 at 2:34pm
A man moves on his bike with 54km/h and takes u- tune (180 degree)and continues it speed to move with same speed .the time of u-tune is 10sec.find its average accleration
Wednesday, July 2, 2014 at 2:20pm
Abox of mass 60kg starts from the rest at height h and slides down a rough slope of length 10m, which makes an angle of 25 degree with the horizontal. It undergoes a constant acceleqation of magnitude 2m/ while sliding down the slope. Calculate the work done on the box by the ...
Wednesday, July 2, 2014 at 12:06pm
Which way is the momentum occuring if a child is riding a merry go round at a constant speed. So for example at each 4 "sides" of the merry go round which direction is momentum . I know the velocity is always tangent to the circle at a specific point. does the ...
Wednesday, July 2, 2014 at 9:37am
Air pressure at the surface of a fresh water lake near sea level is about 10^5 N/m2. At approximately what depth below the surface does a diver experience a pressure of 3.0 e5 N/m2?
Tuesday, July 1, 2014 at 5:57pm
A 25 kg box is being pushed across the floor by a constant force 100, 0, 0 N. The coefficient of kinetic friction for the table and box is 0.15. At t = 6.0 s the box is at location 14, 3, −4 m, traveling with velocity 6, 0, 0 m/s...
Monday, June 30, 2014 at 9:27am
What effect does friction have upon a) ball bounce angle, and b) speed of the court? Refer to clay and grass courts to help illustrate your answer. (4 marks) please help!
Monday, June 30, 2014 at 6:52am
Equation for the reaction which took place: Hydrochloric acid + calcium carbonate -> calcium chloride + carbon dioxide + water When the reaction stopped the total mass had decreased from 102.5g to 101.4g. some water had evaporated from the beaker what else caused the drop ...
Sunday, June 29, 2014 at 10:26am
To have a high work effiency of concrete batching plant,we need to know the maintance of it to extend its useful life.We have study this for a long time and it includes two aspects. One is lubricating the shaft of concrete batching plant when it works every single time to ...
Thursday, June 26, 2014 at 11:11pm
As the United States is one of the largest contributors to atmospheric carbon emissions, what specific policies might the United States enact to reduce its impact on global climate change? Using at least two scholarly or reputable resources and your textbook, discuss the ...
Thursday, June 26, 2014 at 2:59pm
An athlete runs from one end to the other end of a semicircular track whose radius is 70m.what is the total distance covered by the athlete and what is his displacement?
Thursday, June 26, 2014 at 11:44am
A car of mass 2900 kg collides with a truck of mass 4800 kg, and just after the collision the car and truck slide along, stuck together. The car's velocity just before the collision was < 34, 0, 0 > m/s, and the truck's velocity just before the collision was <...
Wednesday, June 25, 2014 at 7:52pm
A bullet of mass 0.062 kg traveling horizontally at a speed of 150 m/s embeds itself in a block of mass 90 kg that is sitting at rest on a nearly frictionless surface What is the speed of the block after the bullet embeds itself in the block?
Wednesday, June 25, 2014 at 2:46pm
In this problem, you will explore the protein lysozyme. Lysozyme is present in hen egg whites and helps to protect the developing chick from bacterial infection by destroying the cell wall of certain bacteria. Lysozyme does this because it is an enzyme, a protein that ...
Wednesday, June 25, 2014 at 2:41pm
A moon orbits a planet in the xy plane, as shown in the figure. You want to calculate the force on the moon by the planet at each location labeled by a letter (A,B,C,D). At each of these locations, what are (a) the unit vector r, and (b) the unit vector F in the direction of ...
Tuesday, June 24, 2014 at 8:19pm
Which best explains why the shore of a lake heats up faster during the day than the lake's water? A.water gives its extra heat to the land. B.water reflects more of the sunlight. C.water let's most of the light go to the bottom. D.water gives much of the heat to the ...
Tuesday, June 24, 2014 at 4:03pm
prepare an inclined plane by using a plane card board sheet, inclined at different angels, using a toy car find the distance covered for different angels, plot graph between the angle of inclination and distance travelled. find the angle for maximum and minimum distance
Tuesday, June 24, 2014 at 1:09pm
Find the mass of potassium chloride and volume of oxygen at STP liberated when 0.5 moles of potassium chlorate are heated.Also find the moles and mass of oxygen evolved.
Sunday, June 22, 2014 at 3:48am
IN A CLASS OF 130 STUDENTS.85 PASSED IN MATHS, 60 PASSED IN SCIENCE, 10 FAILED IN BOTH. a) how many passed in science but failed in math b)how many failed in exactly one subject
Saturday, June 21, 2014 at 9:40am
Maths literacy,history,life science,english,xhosa,life orantation,geography.
I'am doing grade 11 now and when i passed grd 12 next year.i want to know what caree is good for my subjects ,because i don't know what caree should i take.
Wednesday, June 18, 2014 at 5:27pm
Imagine that you have a rectangular swimming pool, but you have no idea how deep it is. You know that the pool has a volume of 216 m3 . You measured the dimensions of the pool and found that it is 15 m long and 6 m wide
Wednesday, June 18, 2014 at 9:30am
is the work needed to bring a car's speed from 0 to 10 km/h less than. qual to. or more than the work needed to bring its speed from 10 to 20 km/h? in the amounts of work are different, what is the ratio between them?
Tuesday, June 17, 2014 at 2:10pm
1. Why is ice a faster surface for sleddikng than snow? a. Ice is flatter than snow. B. Ice is colder than snow. C. Ice provides less friction. D. Ice has less mass than snow. My answer- A
Tuesday, June 17, 2014 at 11:57am
4. A Beers Law plot was prepared for the reaction A(aq) + B(aq) AB(aq), plotting absorption over AB(aq) concentration. The linear equation for this plot was y = 78.3x. A solution was prepared by mixing 10.0mL of 0.100M A with 5.00mL of 0.100M B and adding enough ...
Monday, June 16, 2014 at 7:58pm
A rod of length L=1.80m is mounted to a wheel (solid cylinder) of radius R=8.00cm. A massless rope is wound on the wheel, and then connects to a block of mass m=0.250kg. The mass is released from rest and allowed to fall. 1. Find the tension in the rope. 2. How long does it ...
Monday, June 16, 2014 at 6:45am
Kyle has struggled to feel comfortable in science classes with labs since his junior year of high school, when a solution he was working with ignited. He was always cautious with chemicals but his lab partner that year enjoyed seeing what would happen when he mixed random ...
Sunday, June 15, 2014 at 11:53am
I REALLY REALLY NEED HELP SO 1.I need to do an essay asking you (me)to explain what is the difference between erosion,transport,and deposition?... 2.another essay asking me to explain you (me) to explain the destructive and positive effects of a volcanic erupyion?... 3.a short...
Saturday, June 14, 2014 at 4:24pm
What form of pollution, if any, does each energy source cause? How does the economy influence energy source choices? How does location influence energy source choices?
Friday, June 13, 2014 at 8:42pm
science (check please (:)
Luther Burbank was a plant breeder who developed a strain of potato plant that produced more tubers (the part of the root that people eat) of larger size than other potato plants that were grown on farms at the time. This strain of potato was also resistant to the potato ...
Friday, June 13, 2014 at 5:56pm
science (CHECK plz)
How did Lamarck and Darwin differ in their thinking about species? A. Darwin thought that organisms could induce their own changes, while Lamarck thought that change could only be induced by an organism's environment. B. Darwin thought that change could occur in individual...
Friday, June 13, 2014 at 11:48am
science (check plz)
1)When evolution was first proposed, which of the following was used as evidence to support the idea? A)observations of nature B)laboratory experiments C)extensive fossil collections*** D)genetic sequences
Thursday, June 12, 2014 at 11:35pm
science (check please (:)
suppose a species od flowering plant produces primarily blue flowers but also some very pale blue (almost white) flowers the blue color attracts pollinators but the white color does not herbivores feed on this plant and locate it by its blue flower color the white flower color...
Thursday, June 12, 2014 at 6:34pm
science cant figure it out
4 What do scientists now think about the pace of evolutionary change? A Gradualism best explains the pace of evolutionary change. B Punctuated equilibrium best explains the pace of evolutionary change C A combination of both gradualism and punctuated equilibrium explains the ...
Thursday, June 12, 2014 at 3:02pm
Darwin assumed that evolutionary change was always slow and gradual. What was the first evidence that suggested evolutionary change might happen fast sometimes? a. homologous structures b. fossils c. reproduction rates*****? d. DNA sequences
Thursday, June 12, 2014 at 2:46pm
physical science(chemistry change)
Experiment of tiratic oxilic acid wih mass 4,5g and volume of 25ml,nd concentration of 0,05mol.dm.3 against volume of 14ml and 1,79mol.dm3 sodium hydoxide to determine the concentration of sodium hydroxide,,show all the working,aim,results,observation of result,discussion
Thursday, June 12, 2014 at 12:05pm
physical science(chemistry change)
Experiment of tiratic oxilic acid wih mass 4,5g and volume of 25ml,nd concentration of 0,05mol.dm.3 against volume of 14ml and 1,79mol.dm3 sodium hydoxide to determine the concentration of sodium hydroxide,,
Thursday, June 12, 2014 at 12:04pm
Electrons are emitted from a conductor when the conductor is A. subjected to a small voltage. B. exposed to weak light. C. bombarded by high-speed electrons. D. cooled rapidly.
Wednesday, June 11, 2014 at 6:18pm
When an electron is displaced in a semiconductor, the hole that's left behind is A. attracted to the negative terminal of the voltage source. B. attracted to the anode of the voltage source. C. incapable of carrying a charge. D. considered and impurity in the crystal.
Wednesday, June 11, 2014 at 6:15pm
The air pressure on Pikes Peak in Colorado is approximately 600 millibars. What is the relationship between air pressure at the top of Pikes Peak and at sea level, where air pressure is 1013 millibars?
Tuesday, June 10, 2014 at 1:23am
Computer Science!!!! Help!!!
The book is not doing anything for me. Anyone know where I can find step by step tutorial of this? Specifically for Visual Basic 2012? And not just a simplified version, I mean EXACTLY how to do this. I have been looking through YouTube, my textbook (An Introduction to ...
Monday, June 9, 2014 at 7:40pm
A uniform disk with radius 0.320m and mass 28.0kg rotates in a horizontal plane on a frictionless vertical axle that passes through the center of the disk. The angle through which the disk has turned varies with time according to è(t)= (1.20rad/s)t + (8.70rad/s^2)t^2 my...
Monday, June 9, 2014 at 2:04pm
a 50kg mass is suspended from a spring, causing it to extend by 30mm. calceolate the spring stiffness? The mass is then pulled down a distance of 90mm and released. calculate the frequency of the resulting motion, assuming that this is simple harmonic, calculate the velocity ...
Monday, June 9, 2014 at 1:18pm
science (Eating and allergies)
Well, can people be allergic to seeds? Recently I have been throwing up after eating. I realised everything causing my sickness was seeds, but I feel like no one else has this. I've eaten tomatoes ( I don't like them but it was in my mum's pasta sauce) and the ...
Sunday, June 8, 2014 at 4:29am
Science - chemistry
The SO2 present in air is mainly responsible for the phenomenon of acid rain. The concentration of SO2 can be determined by titration against a permanganate solution of known concentration as follows: SO2 + MnO4^-1 -> SO4^-2 + Mn2+ (unbalanced) Balance the equation showing ...
Sunday, June 8, 2014 at 3:03am
A solution that contains a large amount of salt and a small amount of water is said to be a __________ solution. A. dilute B. unsaturated C. concentrated D. saturated
Saturday, June 7, 2014 at 8:43pm
2. Two identical masses are moving down a slope. One mass is traveling twice as fast as the other mass. How does the kinetic energy of one mass compare to the other? (1 point) The faster object has the same kinetic energy as the slower object. The faster object has less ...
Saturday, June 7, 2014 at 5:10pm
Classify each of the following as examples of kinetic or potential energy. a) a car driving along a level road. b) an elastic band is stretched to twice its normal length c) a book is at rest on the top shelf of a bookcase d) a lightning bolt produces thunder that travels at ...
Friday, June 6, 2014 at 8:13pm
10. Which soil layer contains the most humus? (1 point) A horizon B horizon C horizon D horizon its the O horizon, i know this. But i guess it wants you to tell which is closest 14. Which of the following usually causes creep? (1 point) volcanic activity freezing and thawing ...
Friday, June 6, 2014 at 6:45pm