Science

Recent Questions

physical science
An input force of 20 newtons is applied to a lever at a distance of 2 meters from the fulcrum. An object 0.5 m away from the fulcrum (and on the other side) is lifted by the 20-N force. What is the output force? A. 10 N B. 20 N C. 40 N D. 80 N

Science
What is the mass if a bag if its weight is 9.5N? What is its weight when it is brought to the moon?

science
Time of evaporation of 250ml of water at room temperature

science
An astronaut has a mass of100kg. She recedes from her spacecraft using spurts of gas from a small unit on her back. If the force generated by the gas spurt is 50N, calculate her acceleration.

physical science
A car is driving at an average speed of 100km/hr for 2 hours, then drives an average of 50.0km/hr for one hour. what was the average speed of the 3 hours? 100.0km/h 100.0km/h +50.0km/h =250.0km/3h 250.0km/3h divided by 3h =83.3km/h

Science Help. Thank You! (:
What are the three of the most widely used energy sources in California?

Science 207
Lab 2 – Water Quality and Contamination Experiment 1: Effects of Groundwater Contamination Table 1: Water Observations (Smell, Color, Etc.) Beaker Observations 1 2 3 4 5 6 7 8 POST LAB QUESTIONS 1. Develop hypotheses on the ability of oil, vinegar, and laundry detergent to ...

Science 207
Lab 2 – Water Quality and Contamination Experiment 1: Effects of Groundwater Contamination Table 1: Water Observations (Smell, Color, Etc.) Beaker Observations 1 2 3 4 5 6 7 8 POST LAB QUESTIONS 1. Develop hypotheses on the ability of oil, vinegar, and laundry detergent to ...

Science
When you change the dna code to mRNA, will A become U or T?

science chemistry
A basic amino acid,arginine,has a molar mass of 174g.mol^-1.it has the following percentage composition:41,38% carbon, 18,39% of oxygen,32,18% of nitrogen and 8,O5% of Hydrogen.determine the molecular formular of arginine

queen's science Academy
A stone is dropped from the top of a tall building and at the same time another stone is thrown vertically upward from the ground level with a velocity of 20m/s the stones meet exectity 2s after their release how tall is the building

science chemistry
A given mass of helium(gas)occupies a volume of 3,6m^3 at a pressure of 105 kPa.if the temperature remains constant,calculate volume of the gas if the pressure is decreased to 70 kPa.

science chemistory
CaCO3 2HCl forms CO2 CaCl2 H2O 1.calculate the molar mass of calcium chloride produce 2.calculate the number of moles of calcium carbonate 3.calculate the mass of calcium carbonate

physical science chemistry
Fill in the missing words Ionisation energy, water, melting point, electronegativity, non-polar, solvent, pair, boiling points, polar A covalent bond is formed when a 1________ of electrons is shared between the bonding atoms.when the electrons are shared equally,a 2_______ ...

Science
Marie and Pierre Curie coined which term to describe the ability of certain elements to give off radiation spontaneously? Florescence Rarefaction Radioactivity** Electromagnetic (**=my answer)

Science living environment Regents
When you change the dna code to mRNA, will A become U or T?

Computer Science
A public transport company provides three types of transports to its passengers to travel from city A to city B of different state. The three types of transports are train, bus and taxi. Each transport has different charges and maximum seats limit. The table below shows the ...

Science
If you have a rocket with a mass of 30.0 kg, how much thrust will be needed to have a thrust to weight ratio of 3:1?

Science
1. Two 20.-newton forces act concurrently on an object. What angle between these forces will produce a resultant force with the greatest magnitude? (1) 0° (2) 45° (3) 90.° (4) 180.° 2. A rock is thrown straight up into the air. At the highest point of the rock’s path, ...

Science
Two 20.-newton forces act concurrently on an object. What angle between these forces will produce a resultant force with the greatest magnitude? (1) 0° (2) 45° (3) 90.° (4) 180.°

science
) If an ocean is opening at a rate of 5 cm/year and it has been doing so at the same rate for 10 million years, approximately how wide is that ocean?

science
5 L OF H2 GAS WAS COLLECTED OVER WATER AT 25 CELCIUS AND 750 MM PRESSURE CALCULATE THE VOLUME OF DRY H2 AT STP AQUEOUS TENSION AT 25 CELCIUS IS 23 MM

Science
I have 59.73 grams of a solid dissolved into water. The total is now 115ML of water. I added the water into a beaker already containing said solid. I did not measure how much water I put into the beaker. 59.73g/115ML=0.51g/ML My question is. Is this the correct way to mix and ...

science
after starting from rest, a car acceleraters uniformly 1.2 m/s^2 for 20 s. it then continues driving at a constant velocity for 19s longer. what is the average velocity for 39 s ?

Science
What is the density of a substance with a mass of 0.0450 kg and a volume of 26.4 ml

science
Two velocity each 5 ms/s are inclined to each other at 60degree. Find their resultant

Science
One of the most common commercial methods for the production of pure silicon that is to be used for the manufacture of semiconductors is the Siemens process (see Figure P5.3.5) of chemical vapor deposition (CVD). A chamber contains a heated silicon rod and a mixture of high-...

science
Ram is 35 kg sitting 120 cm away from the pivot while Hari is 30 kg sitting at another end of seasaw. How far should Hari sit from the pivot point? Calculate

SCIENCE
Joseph jogs from one end "A" to another end "B"of a straight road in 300 metre in 2 minutes 50 seconds and then turns around and jogs 100 metre back to point"c"in another 1 minute.What is the Joseph'S average speed and velocity from "A"to"B" "A"to"c"

science
Which of the following properties of water explains its characterization as the universal solvent? Which of the following properties of water explains its characterization as the universal solvent? A. Kinetic energy of liquid water molecules B. High specific heat C. Polarity ...

Kainantu sec..science(chemistry)
How many moles of O2 are there in the above sample at the initial temperature and pressure?

Kainantu sec..science(chemistry)
A sample of O2 gas occupies 1.93L at a pressure of 10.0atm at 100 degree celsius. What volume will the sample occupy at stp?

Kainantu sec..science(chemistry)
At stp what volume of SO2 gas will be produced when 2.00g of CS2 is burned

Science
how many of earth's atmospheres is on you at sea level?

science
Two forces P and Q whose resultant is 10Newton are at right angles to each other. If P makes 30 degrees with resultant.Show me the workings of the magnitude of Q in Newton and the diagram of the vectors.

science
A car is travelling at 20m/s along a road. A child runs out into the road 50m ahead and the car driver steps on the brakes pedal. What must the car’s deceleration if the car is to stop just before it reaches the child?

meyisi s s s
geography, life science, history, l o , maths lit, english and xhosa

science
Arthropoda Chelicerata Merostomata (horseshoe crabs) Arachnida (spiders, mites, scorpions) Pycnogonida (sea spiders) Crustacea Copepoda (small crustaceans) Cirripedia (barnacles) Malacostraca (crabs, lobsters, shrimp) Uniramia Insecta (insects) Chilopoda (centipedes) Diplopoda...

physical science
A man applies a force of 150N to pull a 20kg box with a rope that makes an angle of 60percent with the horizontal.The box experience a kinetic friction of 15N. Calculate the acceleration of the box.

Science
A species of flowering plant produces vibrant blue flowers. The flowers attract both pollinators that spread the plant's pollen and herbivores that feed on the plant. An adaptation occurred through several generations of plant species, and the plant is now known for its long, ...

science
A NEGLIGIBLY SMALL current is passed through a wire of length 15 m and of uniform cross-section 60x 10^7 m2 and its resistance is measured to be 50.what is the restivity of the material at the temperature of the experiment.

science
Calculate the volume of solution that has a vapour pressure of 25.8 mbar and contains 200.3 g of galactose, C6H12O6, at a temperature of 22.0 °C. The vapour pressure of pure water at 22 °C is 26.40 mbar, the density of water is 1.00 g mL-1, and assume no change in volume ...

Science (Physics)
A conductor carries a current of 25 A and is at right angles to a magnetic field. The flux density is 0.8 Tesla and the length of the conductor in the field is 35 cm. Calculate the force acting on the conductor, and the value of the force if the conductor is inclined at 35 ...

Physical science paper 1 june exam
What is Reflection?

science
An electromagnetic calorimeter made of Pb that has inside a Co-60 source with the activity 4 Ci.The two gamma rays emmited have the energies 1.173 MeV and 1.332 MeV. Calculate the time after that the temperature of the calorimeter rises with T=10 K. C=92J/K (for Pb)

Science--HELP!!
Can you please check my answers: 1. Dalton's idea that atoms cannot be divided into smaller parts was disproved by the discovery of _________ (electrons?) 2. The description of the structure of the atom is called ______ (atomic model?) 3. In a water molecule, two atoms of ...

Science
What do B cells do?

Science
If 15% of the radioactive material decays in 5 days, what would be the percentage of amount of original material left after 25 days?

paramedic science
The male person on-scene is complaining of abdominal pain but refuses any treatment or transport going against your advice. He has obvious bruising to his abdomen consistent with a seatbelt injury. Using Queensland Ambulance Service protocols as a guide - discuss what steps ...

Science
A 13.0 kg block of concrete rests on a 5 cm by 2 cm board. What is the acceleration of the block of concrete here on Earth?

science
1. The images above show particles in a medium. Which of the following shows the worst conditions for a sound wave travel? A B C D is the answer A? Which of the following correctly describes a radio wave? A long wavelength and high frequency B long wavelength and low frequency...

science
Light waves strike a lamp shade. What property of light is demonstrated? diffuse reflection* diffraction refraction regular reflection

Science
Which of the following correctly describes a radio wave? long wavelength and high frequency long wavelength and low frequency short wavelength and low frequency short wavelength and high frequency 3. When the energy of a light wave is transferred to a particle and causes it ...

science
I want to write a CV , could you help and notice me how to do it ? with respects

science
electric charges that are different A. attract each other B. Repeal each other C. exist in pair D. DO not interact

Science Help Plzz
1. The images above show particles in a medium. Which of the following shows the worst conditions for a sound wave travel? A B C D is the answer A? Which of the following correctly describes a radio wave? A long wavelength and high frequency B long wavelength and low frequency...

Earth science
Hello! Does Jiskha have Earth Science tutors? If not, could someone direct me to a site where I could ask for help? My questions regard finding out specific heat capacity and heat of fusion and heat of vapourization of water. Thank you!

science
Could someone who goes to connexus academy Please please please give me the answers to Human Impact on the Environment Unit Test pretty please im stressed out and im backed up.please please help i will repay you! please!!!! and please may they be the CORRECT answer. Thank you ...

Science
A plane is flying horizontally with speed 215 m/s at a height 2770 m above the ground, when a package is dropped from the plane. The acceleration of gravity is 9.8 m/s^2. Neglecting air resistance, when the package hits the ground, the plane will be _________. Can anyone ...

Science
Calculate the energy of a photon of ultraviolet light of wavelength 200nm

Science
Which of the following is not a characteristic of natural selection? A. More offspring are born than will survive to reproduce. B. Mutations appear randomly. C. Breeding pairs are chosen by humans. D. Organisms that are better adapted are more likely to survive.

Agricultural Science,Business Studies,History,Life Orientation.
I do the following subjects:Agricultural Science,Business Studies,History,Life Orientation and Two Languages.And Im wondering What kind of A Job can I get and which college/university can Go to? .. Please Help

Science
When 1.23g of ethanol (delta c Hm = -1368kj/mol at 25 C ) is burned in an adiabatic flame calorimeter, the temperature increases by 8.6 C. Under the same experimental conditions, when 1.14g of 1-propanol is burned, the temperature increases by 9.0 C. What is delta c Hm for 1-...

Science
A solution containing 3.22g of solute in 40.0g of 1,4-dichlorobenzene and its freezing point is 49.2 C. Calculate the molar mass of the solute.

science
1. Descriptive statistics are widely used in qualitative research. When establishing if a population is normally distributed explain when the statistics of sample size, mean, mode, median, skewness and kurtosis will guide the researcher to make conclusions of a normal ...

Science
What is the percentage composition of copper, Cu, in Cu20? A. 44% B. 80% C. 89% D. 133% I Choose C, Am I correct?

science
A ball with a mass of 3.47 kg is rolling along at 17.4 m/s. If you apply a force of 52.2 N to it, how many seconds will it take to stop?

science (cladogram)
How would a scientist use DNA or protein sequences from three different organisms to construct a cladogram?

science
What is the power of a 900 n force applied over a distance of 40 m for 45 sec?

science
the ratio of velocities of two object a and b is 1:3. if the position-time graph of object a is inclined to time axis at 30degree then the position-time graph of object b is inclined to time axis at

Science (theory of evolution)
How would a scientist use DNA or protein sequences taken from three different organisms to construct a cladogram.

Science
Assuming a warm front is moving into the area, there is a stignant (non moving) cold air mass around New York, what type of precipitation might be expect? How long might it last?

Science
If it is snowing in Great Neck, what type of air mass must be present?

Science
Why can cold air masses from Canada make it all the way down to the Gulf of Mexico?

Science
Describe what would happen if a positively charged sodium ion and a negatively charged chlorine ion came into contact?

science
What happens when a warm humid air mass meets a cold dry mass?

Science
Why are Canadians air masses considered to be dry air masses?

science
How would a scientist use DNA or protein sequences taken from three different organisms to construct a cladogram.

Science
If the volume of a balloon is 5.0 L at 22 degrees Celsius, what will be the new volume if the balloon is heated to 75 degrees Celsius? Should the volume increase or decrease? 5/22=x/75 x=17.045

Science
Which of the following describes the use of a renewable energy source? A. using natural gas to heat a house B. using a windmill to grind grain C. using petroleum to run a car D. using coal to generate electricity I think the answer is B.

Science (Physics)
A 33.3 kg cyclist is riding a 10.7 kg bicycle at a velocity of 7.0 m/s. If the cyclist applies a brake that applies a force of 42.7 N, what is the time required for the cyclist to come to a stop?

science
which of the following has the largest nos of oxygen atom. 1- 1 gm of oxygen atom 2- 1 gm o^2 3- 1 gm of ozone

Science
I need help with questions regarding information about the Galapagos Island volcano. 1. where is the volcano located 2. how long has it been active 3. what kind of volcano is it 4. is it dangerous 5. what is the surrounding area like 6. what else is there to do in the ...

science
Why does a light go out when you turn off the wall switch? A. The switch changes the direction of the flow of electrons. B. The switch causes a break in the circuit. C. The switch changes the circuit from series to parallel. D. The switch absorbs the electrical energy.

Science (theory of evolution)
How has the fossil record support the theory of evolution?

Science (theory of evolution)
How has the genetic code support the theory of evolution?

Science
What are some unexplained aspects of the future of fossil fuels and other energy?

science
what happens to insulin when kidney failure happens?

science
A ping pong ball and a penny are placed in water. The ping pong ball floats while the penny sinks? What property of water does this demonstrate? I think it has to do with the density. The reason the ping pong ball floats is because it has a lower density than the water. The ...

science
If A represents atomic mass and Z represents atomic number, which of the following describes an atom after a proton is emitted from its nucleus? A. A+ 1, Z + 1 B. A-1,Z-1 C. A+ 1, Z-1 D. A-1, Z + 1 My answer is B

earth science
_____ currents assist in the transfer of energy from warmer climates to cooler climates

4th grade Science (Please Help!)
Bowl A and Bowl B are filled with the same amount of water. Bowl A is covered in plastic wrap. Both bowls are left on a counter. The water level is checked in both bowls after 1 week. What is the independent variable? PLEASE HELP.

4th grade Science (Please Help!)
Bowl A and Bowl B are filled with the same amount of water. Bowl A is covered in plastic wrap. Both bowls are left on a counter. The water level is checked in both bowls after 1 week. What is the hypothesis? Please HELP!

Science
what is the combination of waves?

science
What are some scientific terms for metal rust

Science
When an oxygen atom forms an ion, it gains two electrons. What is the electrical charge of the oxygen ion? A. +2 B. -1 C. -2 D. +1

science
Plant-deer-tiger The first step in the energy chain that created the bonds of proteins in the tiger's muscle cells in the food chain shown above is A. deer the tiger ate B. plant the deer ate C. photons the sun made D. carbohydrates the plant made I think its A because by ...

science
Moths with certain coloring are camouflaged in their habitat. Over time, more moths are born with this coloring. Which of the following best explains the increasing number of moths with this coloring? A. Natural selection B. Gene flow C. genetic drift D. sexual selection I ...

Science
A spherical object made of stone is dropped into a container of water and sinks to the bottoms of the container causing 30N of water to spill out. What is the estimated gravitational force of the object?

Science and maybe re
This isn't really homework, but I thought someone could really help me with this. Did time exist before the Big Bang? I believe in God; if time always existed, why did he make it wait? Looking for a really scientific explanation. Thanks!

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