# Science

## Recent Questions

Science
Calculate the mass of 3.20 mol of sodium hydroxide, NaOH. M(NaOH) = 40.0g mol-1 Would the following be the correct workings? n= 3.20 mol M=40.0g mol-1 m(NaOH) = n x M = 3.20 mol x 40.0g mol-1 = 128 g NaOH Is this the correct workings?

maths,science, physics
A toy locomotive of mass 420g moving at 30cm s^-1 south collides with a carriage of mass 200g moving at 30cm s^-1 north. If they become couple together, what is their common velocity after the collision?

maths,science, physics
A bullet of mass 20g is fired from a rifle of mass 4kg with a speed of 500ms^-1.Calculate the initial velocity of the recoil of the rifle.

maths,science, physics
A mass of 2kg resting on a smooth level table is connected by a light in extensible string passing over a frictionless pulley to a suspended 3kg mass (imagine as shown on the diagram).Find: I.The tension in the string. II. The magnitude of the acceleration of the two masses. ...

maths,science, physics
A small cart of mass 300g when emty can move freely on a horizontal surface. The cart contains 100g of sand and moves initially with speed of 18cm s^-1. a)what would be the speed of the cart if a further 200g of sand were dropped vertically into it from a stationary container...

maths,science, physics
A truck of mass 4×10^3 moving at 3.5 ms^-1 collides with a stationary truck to which it becomes automatically coupled. Immediately after the impact the trucks moves along together at 2 ms^-1 in the same direction. Find the mass of the second truck.

science
The 140-million year-old fossil of a tortoise was recently found about 700 meters deep in a coal mine in northeast china. Scientists studying the fossil believe that it represents a previously unknown species? Which of the following is the best conclusion based on the data ...

English
Hello. Dear Ms.Sue, I would be very grateful for your advice. 1) Do you think it's possible to say "the holistic phenomenon of science" (meaning "science as a whole")? 2) Do you think I used the articles correctly in the following "the interaction of the cultural, public and ...

science
Ms. Sue did you forget about my other questions?

science
right-handers exhibited an equal or more active brain response in slightly more than one-fourth of the drug trials, compared to left-handers. This statement should be classified as 1 the problem= the main issue or subject being investigated in the study 2 a method= a procedure...

science
After drugs were administered, the brain activity of each person was recorded. This statement should be classified as 1 the problem = the main issue or subject being investigated in the study 2 a method= a procedure , process, or approach used to investigate the problem 3 a ...

science
Can someone please check my other answer from Saturday June 5 @ 10:29 please thank you ?!

science
left-handed people demonstrated greater brain activity than right-handed people when under the influence of drugs. This statement should be classified as 1 the problem =the main issue or subject being investigated in the study 2 a method = a procedure, process, or approach ...

science
3.5g of zinc react with excess dilute hydrochloric acid to produce hydrogen gas at STP,calculate mas of hydrogen gas produced

Science

Science
Using A Well Labelled Diagrams,briefly Describe How You Would Determine The Density Of An Irregular Objects

science
What is a balanced chemical equation for the combustion of cooper?

Science
If 100 bacteria get into our body and reproduce every 20 minutes how many will there be in 2 hours?

science
why do primitive organism have lesser number cells as compared to more advance form?

Science
I've been asking questions and all you so called "helpers" (such as Reed, Writeacher, etc.) you are all being sarcastic. I have no interests to cheat, but you don't listen to my side notes. I am going to ask one more question, and again, be don't be sarcastic. Question. Why is...

science
the brains of left handers may be more sensitive to drugs, says a Swiss researcher, that may be why more people are right handed. Peter Irwin of the chemical firm Sandoz limited, in Basel, gave 88 subjects 12 different drugs, the used electroencephalograms (EEG) to record ...

science
could you use potassium nitrate to test for fluoride in mouth rinse? Is potassium nitrate a water soluble.?

science
Three equal-sized pans containing distilled (pure water),ocean water (3 percent salt),and water from the Great Salt Lake in Utah (about 20 percent salt)are placed in freezer. Which of the following would be the order in which these three liquids would freeze? 1 distilled water...

science
which of the following would be a disadvantage of boiling food in salted water rather than using pure water? 1 A only 2 B only 3 C only 4 D only 5 A and D only B ONLY is the answer?!

Science
A machine has velocity ratio of 5 and is 60% efficient. What effort would be needed to lift a load of 200N with tge aid of this machine?

science
Find the angle of friction when rod starts sliding

Science
The Haber-Bosch process, devised in the early 20th century, revolutionized global industry. It provides a way of “fixing” atmospheric nitrogen into ammonia, allowing for the production of fertilizers and the many nitrogen-based chemicals we use today. The reaction is ...

Science
Why are boats more efficient than airplanes? They use less fossil fuels to move

Earth Science
Why are boats more efficient than airplanes? They use less fossil fuels to move

Political science
what does realism explain best and what does it miss? what does liberalism explain best and what does it miss? what does radicalism best explain and what does it miss? what does Constructivism best explain and what does it miss?

science
A locomotive train is on its way from Chicago, IL to Madison, WI. The trip is said to last 3.15 hours. When the train arrives in Madison the conductor notices it actually took them 3.26 hours. The train company prides itself on always having its trains to the station within a ...

Science
1.Asolid sphere has amoment of inertia of 0.8kgm2&diameter 10cm rolls down along an inclined plane of length 80cm which is inclined at 37` to the horizontal .What is the transitional momentum of the sphere as it reaches to the foot of the inclined plane?

A 230 kg steel crate is being pushed along a cement floor. The force of friction is 480 N to the left and the applied force is 1860 N to the right. What is the acceleration of the crate? (Hint: remember to find net force first) a=6.00 m/s2 a=28.1 m/s2 a=8.10 m/s2 a=6.0 m/s2

A 230 kg steel crate is being pushed along a cement floor. The force of friction is 480 N to the left and the applied force is 1860 N to the right. What is the normal force? A. 480 N down B. 480 N up C. 2300 N down D. 2300 N up

A 230 kg steel crate is being pushed along a cement floor. The force of friction is 480 N to the left and the applied force is 1860 N to the right. The forces acting on the crate are __________________. A. balanced B. unbalanced

science
a body of mass 2 kg is thrown vertically upward with kinetic energy 245 J. The acceleration due to gravity is 9.8m/s^2 the kinetic energy of the body will become half at a hieght of

science
Forces of 23 N and 41 N act at a point and are inclined at 90° to each other. Find, by drawing, the resultant force and its direction relative to the 41 N force.

Science
Explain how you would prepare 250cm^3 of 0.2 m NaOH.

Science
Arrangethe increasing of bp for given molecule and given reason h2o, h2s, h2se. H2te

English
Khianna is preparing an informational presentation for her science class. Her presentation discusses three different theories about what killed the dinosaurs 65 million years ago. The first theory is that an asteriod hit the earth, the second theory is climate change, and the ...

Science
4MV=4×?V

English
Dear Ms.Sue, thank you so much for your help. Please help me with a few more problems. 1) "the thesis defines the integrity and continuity of the process of the emergence of natural science" (maybe too many OF?) 2) "its nature is displayed in the(?) influence on and by society...

Science
A force of 32.3 N is applied to a 5.87 N box resting on a table. If friction acts with a force of 2.11 N, what is the acceleration of the box?

help me fill me fill in the blanks please??? My options:adaptation, body, homologous structures, inheritance, older, artificial selection, overproduction, punctuated equilibrium, common ancestor 1) Similarities in the early development of chickens and opossums suggest that ...

science
Why do human beings use running shoes,winter boots, skis, or flippers? Why are these not biological adaptations?

Science
The electric field due to a charged conducting sphere of radius 10 cm , at a distance of 20 cm from the centre of the sphere is 1.5*10pow3 NC-1 and points radially inwards.what is the charge on the sphere ?

Science - Chemistry
How many atoms in a diamond.

science
How can I find the number of mole of 0.25g of CuSO4?

science
When a particle starts from rests and moves with constant acceleration then why its path is always a straight line?

Physical Science
Diamond is a covalently bonded substance made of pure carbon. Each carbon atom has six total electrons so this means carbon shares ________ electron(s) with other carbon atoms. A) one B) two C) four D) six Help Please!

math
Naron is learning for pre-second semester examination. He divides 8 hours per day for learning science, mathematics and literature with the ratio of 2 : 3 : 1. Find the number of hours he studies each major.

Science
A body is moving with an initial velocity of 36km/hr accelerates uniformly at the rate of 4m/s for 15s. Calculate the total distance travelled in 20s and the final velocity?

Maths,Science,geography
Distinguish between folding and faulting

science
explain why the surface tension of water is greater than that of methylated spirit

Math and science
How far apart are these two buildings?

science
If all the nematocysts on a mature man-of-war were filled with poison, what is the total amount of poison (in milligrams) that they would contain? 1. less than one milligram 2. two milligrams 3. five milligrams 4. six milligrams 5. more than eight milligrams I believe the ...

math, science etc
T=(pq/r)-rq make q subject of formula

SCIENCE PLZZ HELP!!!
____ is rate of change of position. Speed Velocity Acceleration Displacement 2. Which of the following is the difference between speed and velocity? direction units speed none of the above 3. A planet is discovered that is the same size as Earth and has the same gravitational...

Basic math for science
A sportswear manufacture determines that the marginal cost of producing x worm-up suits is given in dollars by 20-0.015x.if the cost of producing one suits is \$25,find the cost function and the cost of producing 50 suits and 100 suits

help science
3 simple steps for DNA duplication I have found so many answers but cant get a concise one. 1. separation - of 2 dna strands unzips ? 2. duplicates ? 3. zips back up ? and then a simple sentence about each

Science
A man has a weight of 120kg what will be the Weight of same man on the moon

science
Calculate the osmotic pressure 5% glucose Sol. At 298 kelvin?

science
Which of the following substances would be most effective in relieving the pain caused by a man-of-war sting to one's skin? 1. tap water 2. club soda 3. lipstick 4. perfume 5. lemon juice help this is a hard one

review Question -- 3 simple steps for DNA duplication I have found so many answers but cant get a concise one. 1. separation - of 2 dna strands unzips 2. duplicates 3. zips back up and then a simple sentence about each

science
What can be concluded if the family finds out the lights in the bathroom work, but the floor lamp and tv set still do not work? 1. The electrical service to the cabin has not gone off. 2. The bathroom lights are on the same circuit as the floor lamp and tv set. 3. The floor ...

science
Which of the following statement best describes the two different types of electrical energy involved in the situation above? 1.Both the lightning and the electricity used to light the floor lamp are forms of static electricity. 2. Both the lightning and the electricity used ...

science
Which of the comments are examples of hypothesis suggested to explain what caused the lights to go out? 1. A and D only 2. B and C only 3. C and E only 4. D and E only 5. A, C and E only my best answer is 2

SCIENCE
Which of the following is equal to the buoyant force of a rock placed in a beaker of water? (1 point) volume of the displaced fluid weight of the displaced fluid volume of the rock weight of the rock

SCIENCE HELP
CAN SOMEONE CHECK THESE!! 1. Which of the following is a reason why a person might want to wear snowshoes if walking a distance in deep snow? (1 point) snowshoes spread the person’s weight out snowshoes reduce the amount of pressure on a given spot snowshoes keep the person ...

science
A family is seated around the fireplace in a mountain cabin on a rainy night. A bright flash of lightning lights up the room and is followed in less than a second by a loud clap of thunder. The light bulb in a floor lamp flickers and goes out, as does the TV SET. Fortunately, ...

SCIENCE PLZZ HELP!!!
Given equal concentrations, which of the following produces the fewest hydronium ions in an aqueous solution? strong acid weak acid strong base weak base This is the only question i need help on and i have no clue what ut is! any help?

science
If removed from the life cycle, which of the following would have the greatest impact on the productivity of lawns? 1. robins 2. moles 3. toadstools 4. dandelions 5. microorganisms need a little help here?! I think my answer would be 5

science
Birds extract more food from a lawn than from an equivalent amount of prairie because 1. lawns contain more moisture than prairies 2. prairies occur at a higher elevation than lawns 3. lawns contain more food than prairies 4. temperatures are higher on lawns than on prairies 5...

science
The major advantage provided by worms to a lawn is? 1. attracting birds 2. protecting moles 3. breaking rocks 4. eating weeds 5. cultivating soil I believe my answer is #5 ?!?!

physical science
Name the intermolecular forces in each of the above mentioned substance and water

physical science
Explain why the surface tension of water is greater than that of methylated spirit?

science
What is the equivalent resistance when resistance of 1ohm and 10raise to 6 ohm are connected in series

Social science
India: ______decimal _____ :architecture

science
Chromium (III) iodate has a Ksp at 25°C of 5.0 x 10–6. 125 mL of a solution contains 0.0050 mol L–1 Cr (III) ion. Possible answers: a. 8.4 x 10–2 mol L–1 b. 2.2 x 10–3 mol L–1 c. 6.3 x 10–2 mol L–1 d. 2.1 x 10–2 mol L–1 What is the molar solubility of ...

SCIENCE HELP PLS
How does using coal to generate electricity affect the environment? (1 point) Using more coal reduces the amount of pollution from using oil. Using coal improves the quality of nearby water. Using coal, instead of wood from trees, helps improve the environment. Using coal ...

The following facts are true about Resource A: It grows in nature and takes about five years to reach a mature size. It can be replanted after it is cut down. Resource A is most likely a(n) A inexhaustible resource. B nonrenewable resource. C recycled material. D renewable ...

U.S. History
1. What would this image convey to someone from the early-1900s about about the suffrage movement? (image: "early-1900s women's suffrage painting"-- this has a sign on it that says "official program women's suffrage procession" a person riding a horse and "Washington D.C. ...

science
A bicycle tire is filled with air pressure of 6 atm at a temperature 20 Degrees Celsius. Riding the bicycle on asphalt on a hot day at a temperature 42 degrees Celsius makes the volume of the tire increase by 2%. What is the new pressure in the bicycle tire?

science
Does sodium nitrate turn the phenolphthalein indicator pink ?

What does a cladogram show? A)comparison of the relative ages of organisms B)evolutionary relationships between organisms C)comparison of species that are most similar D)ecological relationships between organisms*** Which pair below has the most shared derived characteristics...

Maths,Physics,Life Science, Agricultural science
list three factors to consider when choosing subject in grade 10

science
imagine you have two identical globes.what type of connection would cause the total amount of light and heat emitted to,, a.less than the amount emitted by a single globe? b.more than the amount emitted by a single globe?

Science
What would the mass of five grams of salt mixed with twenty grams of water be?

earth science
state the mostly reason for the differences in the weathering rate of the three rock materials

algebra
A survey of 70 Customers was taken at a bookstore regarding the types of books purchased. The survey found that 42 customers purchased mysteries, 34 purchased science fiction, 24 purchased romance novels, 18 purchased mysteries and science fiction, 12 purchased mysteries and ...

science
If a steel-density is 7.8g\cm is put in water, will it float or sink

Physical Science
How much heat is necessary to change 305g of ice at -11c to water at 20c

science
If element X has 85 protons, how many electrons does it have? electrons

science
How many grams of zinc chloride are required to react with 15 grams of aluminum metal to create aluminum chloride and zinc metal?

science
if one person is pushing an object to the right and another person is pushing an object to the right like so: 10 Newtons →(object)← 15 Newtons What is the net force? Are the forces unbalanced or balanced? I think the forces are balanced but I'm not sure what the ...

science
A ray of light travels from Liquid helium (n=1.03) into a second material. You gradually increase the angle of incidence until, at 83.6°, the light no longer passes into the second material. What is the index of refraction of the second material?

science
Gallium crystallizes in a simple cubic lattice. Sketch the unit cell. Determine the number of atoms present in the unit cell. The density of gallium is 5.904g/cm^3. Determine a value for the atomic (metallic) radius of gallium.

earth science
When I bumped the table, the coffee in my cup spilled out. Newton's _____ law explains this reaction. 1st 2nd 3rd

science
a radioisotope, Iodine-131, has a half life of 8.1 days. explain what this means. draw a particle diagram for a sample 12 particles of I-131 initially after 8.1 days and after16.2 days.

science
calculate delta E & delta H when 100dm^2 of helium at S.T.P are heated to 373k in a closed container. assuming that the gas behaves ideally and CV=12.55g/mol