# Science

## Recent Questions

science
A 1000kg rocket is set vertically on its launching pad. The propellent is expelled at the rate of 2kg/s. Find the minimum velocity of the exhaust gases so that rocket just begin to rise. Also find rocket's velocity 10second after ignition, assuming the minimum exhaust velocity.

Science
Why is that instantaneous rate of reaction does not change when a part of the reacting solution is taken out?

science
The resistance of 10m long wire is 10 . Its length is increased uniformly by 25% by stretching the wire uniformly. The resistance of wire will change to (approximately) (A) 12.5 (B) 14.5 (C) 15.6 (D) 16.6

Physical Science

Science
Your journey to the centre of the earth took 64 hours at 100km/h. What was the total distance you traveled??

basic science
calculate the work done when a person pushes a car from its stationary position to a distance of 50m applying a force of 200n

Science
A 450-g block is attached to a spring of spring constant 45 N/m and is in simple harmonic motion on a frictionless surface with an amplitude of 7.5 cm. A second identical block, moving at 12 m/s in line with the spring, strikes the first one when the spring is at its maximum ...

Science
CU+H2SO4>CUSO4+H2O+SO2

Science
What mass of iron metal can be obtained from the reaction of 45.6kg Iron (III) oxide Fe3O4 with carbon monoxide CO as given in the following equation? Fe3O4 + 4CO = 3Fe + 4CO2

SCIENCE
a 2cm high object is placed at a distance of 20cm from concave mirror ,the real image is formed at 40cm from the mirror.calculate the focal length,size of image and magnification?

Science
The volume of a gas increases from 18.7 m3 to 25.1 m3 while the pressure changes from 1.82 atm to 1.41 atm. If the initial temperature is 353 K, the final temperature of the gas is K.

science
What are some ways to minimize impacts a water dam creates on the ecosystem?

Math
1. Subtract (4x + 2y) – (8x – 3y). –4x – y 12x – y 12x + 5y –4x + 5y 2. Determine the best name for the quadrilateral. Graphic rectangle rhombus trapezoid parallelogram 3. Which figure has rotational symmetry for an angle of rotation of 270°? graphic graphic ...

Science
What mass of iron metal can be obtained from the reaction of 45.6kg Iron (III) oxide Fe3O4 with carbon monoxide CO as given in the following equation? Fe3O4 + 4CO = 3Fe + 4CO2

Science
What is the equation of the street line that passes through the points 1 and -4 and 3 and 2

Science
A student wants to neutralize 1000 ml of .25m lioh with 0.75m hbr. How much hbr are they expected to use? Sho your work.

Science
what is the concentration of sulfuric acid if 0.25l of it is neutralized by 0.56l of 0.030m koh?

Science
Which symbol correctly represents an element (D) whose atoms contain 15 protons and 20 neutrons? A. 20/15 D B. 15/20 D C. 35/15 D D. 15/35 D C?

Science
Which of the following statements is not consistent with the results obtained in Rutherford’s gold foil experiment? A. The nucleus of an atom is positively charged. B. The nucleus of an atom contains almost all the mass of the atom. C. Atoms are composed mainly of empty ...

Science
In order to analyze the wastewater containing cu2+ from a manufacturing process, 1.0L of water was evaporated to 10.0mL, then placed in a spectrophotometer tube. The absorbance was found to be 0.30. Using your calibration curve, calculate the number of milligram of Cu2+ in 1....

science
a farmer has sown seed too deep. what is he likely going to observe?give reasons.

Science
Shale often contains fossils of leaves. Question: If the gastropods listed in line 3 and line 6 were collected from shale containing leaf fossils what would their possible age be? Question: Could you use radiocarbon dating to assign a numerical date/age to this rock unit? ...

Math
Jason measured rainfall for a science project. Last week it rained 3 1/8 inches in all. This week it rained 1 7/8 inches in one day and 2 3/4 inches on another. How many more inches did it rain this week then last week? Please explain how you got your anwser

Science
what the definition of age range in earth science?

Science ~ Astronomy
Which evidence provides support for the nebular theory: a) scientists have observed the formation of a distant solar system b) the nebular theory has been proven mathmatically c) astronomers have observed protoplanetary disks around distant newborn stars d) none of the above I...

Science
Why Devonian could not be considered an index fossils? How can the occurrence of fossils and their known age ranges be used to date rocks? Need help by understanding the question.

Final length of the bar of copper whose original length was 75mm When heated through 50 degrees

Science
Which of the following is true concerning the Little River Salt Marsh Restoration Project? a. It revolved around restoring tidal flow with culverts. b. It is a 20 year old conservation effort. c. It was immediately successful upon inception. d. It used massive water pumps to ...

Science
How can the occurrence of fossils and their known age ranges be used to date rocks?

Science/Anatomy
I have the formula to the problem but am unsure of my answer.. Problem: Calculate the cardiac output if heart rate (HR) is 90 beats per minute, stroke volume (SV) is 110 ml/beat, end diastolic volume (EDV) is 140 ml, and end systolic volume (ESV) is 30 ml. select corect answer...

Co-efficient of cubical expansion

Final length of the bar of copper whose original length was 75mm When heated through 50 degrees

maths,science, physics
A block of mass 50kg was left to slide down a ramp elevated at an angle of 45 decrease as shown in the diagram below (assume g=9.8 ms^-2). I . Calculate the net force causing the block to slide down the ramp (assume no friction) II. Calculate the net force causing the block to...

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