Wednesday
April 23, 2014

Posts by Mariam


Total # Posts: 84

Chemistry
A student intend to prepare 200ml of 0.3M NaCl solution . The mass in gram of NaCl needed to prepare solution is ?!

Chemistry
To remove temporary hardness we may use ?!!!

Chemistry
A water sample has TDS of 6000mg/l and the total hardness f 60mg/l , the water can be classified as ........

Chemistry
The mass of watch glass is 24.5 g , the mass of watch glass plus white crystals befor drying is 29.1g , and the mass of watch glass and white crystals after drying 27.9 , thus the mass of the white crystals is !????!

Chemistry
If we put a drop of acid in a cup of natural water , the PH will ?

Chemistry
1.2g of NaCl as used to prepare 200 ml solution , what is the molar concentration of NaCl in solution ?

Chemistry
A student mixed 40ml of 0.2m Na2co3 solution with 50 ml f 0.25M cacl2 solution , what is the except number of moles of naclkkw that I will be formed ?

Chemistry
The measured experimental volume of ascetic acid in a sample of vinegar was 7% and the manufacture claimed volume is 5.8% , what is the percentage error ?

Chemistry
What are the Salts are taken into consideration in the calculation of the total alkalinity ????

Chemistry
The separate suspended solid from a solution , we may use .......

Chemistry
In TDS experiment , the mass of the empty beaker was 25.683g , and the mass of the beaker after water evaporated 25.687 g , if the volume of the sample 50 ml , then the TDS of the water sample is ?

Chemistry
In an experiment we have 4 liters of AlAin water in contain or A , and 2 liters of dubai water in contain out B . The alkalinity of water in container A and the alkalinity of water in container B are 50 and 150mg/l as caco3 ,,respectively the alkalinity of water B is 7

Chemistry
In the. Reaction (Na2co3+CaCl2-->2NaCl+caco3) The precipitate is :

Physics
Two forces FA and FB are applied to an object whose mass is 9.53 kg. The larger force is FA. When both forces point due east, the object's acceleration has a magnitude of 1.43 m/s2. However, when FA points due east and FB points due west, the acceleration is 1.28 m/s2, due...

Uos
Two horizontal forces, and , are acting on a box, but only is shown in the drawing. can point either to the right or to the left. The box moves only along the x axis. There is no friction between the box and the surface. Suppose that = +2.6 N and the mass of the box is 4.7 kg....

math
a parabolic bridge over a road is 4 meter tall 4 meter wide and 5 meter long determain the maximum height of a 2 meter truck can drive under the bridge

Physics
Problem 3- A 10-g metal ball is moving to the left with a velocity of magnitude 0.4 m/s has a head-on, elastic collision with a larger 30-g metal ball moving to the right with a velocity of magnitude 0.2 m/s. a) Find the speed of the two balls after the collision. b) If the 10...

Physics
Problem 2- A 15 kg block is attached to a very light horizontal spring of force constant 400 N/m and is resting on a smooth horizontal table as shown in the figure below. Suddenly it is struck by a 3 kg stone traveling horizontally at 8 m/s to the right, whereupon the stone re...

Physics
Problem 1- A 0.5 kg ball is moving to the right at 5 m/s when it is suddenly collide by a wall that exerts on it a horizontal force of 2.5 N for a period of 0.8 s. a) What is the impulse does the force of the wall exert on the ball? b) What is the velocity of the ball after t...

Physics
A400 N child is swing that is attached tow ropes 2m long , find the gravitational potential energy of the child-earth system relative to the red line level when ropes make an angle with the vertical .

Physics
a box initially moving with a speed of 5m/s along a rough , horizontal floor , it stopped it after 5 m the conffenict friction is 0.3 find the work done by friction .

Physics
Problem2-AFor A=-I+2j +5k and B=2j-3k,find: a) The dot productA.B b) The angle between the A and B

Physics
Problem 4: A 250 g block is dropped onto a relaxed vertical spring that has a spring constant of k= 2.5 N/cm. The block becomes attached to the spring and compresses the spring 12 cm before momentarily stopping. While the spring is being compressed, (a) what work is done on th...

Physics
Problem 3- A block of mass m1 = 4 kg moves from rest under the influence of a varying force F(x) = 4x + 38, where F is in newton and x is in meters, on a rough horizontal surface having a coefficient of kinetic friction of 0.2. The block is connected by a light cord passing ov...

Physics
A roller-coaster car has a mass of 500 k when fully loaded with passengers. If at point a the forces exerted by the truck on the car is 15000 What is the acceleration at point A?

Physics
Problem 3- A 40 kg child swings in a swing supported by two ropes, each 3 m long. (a) If the tension in each rope at the lowest point is 350 N, a. find the child's speed at the lowest point. b. the force exerted by the seat on the child at the lowest point. (Neglect the ma...

Physics
Thank you very much Elena

Physics
Problem 2- A 4 kg object is attached to a vertical rod by two strings, as in the Figure. The object rotates in a horizontal circle at constant speed 6 m/s. Find the tension in (a) the upper string and (b) the horizontal string.

physics PLEASE HELP ME
a rubber ball is thrown downwards off a balcony. after it travels 55m it has a speed of 46.5m/s. what is the initial velocity

physics PLEASE HELP ME
A ball rolling down a hill was displaced at 19.6m while uniformly accelerating from rest. If the final velocity was 5.00 m/s what was the rate of acceptation?

Chem
Ores are analyzed by dissolving some of the ore and then performing an analysis of a metal (expressed in grams); usually the concentration of the metal is expressed as % of the amount of the ore (in grams) dissolved. An ore containing V was dissolved and then titrated with MnO...

physics
I have no idea that is why i asked :/

physics
A train moves at a speed 72km/hr. When it approaches the station the driver brakes the train stops in 30 minutes. a) what is the value of deceleration? b) what is the duration it takes to stop?

chemistry
Calculate the amount of zirconium produced (in kg) if a reactor were charged with 261.0 kg ZrCl4 and 25.0 kg Na .

chemisty
What is the density of a 17.12 g object if the dimensions of the block are: length = 12.6 mm height = 9.82 cm width = 0.0140 m

chemistry
What is the density of a 28.87 g irregularly shaped object if the initial volume of water was 24.7 ml and the volume rose to 64.1 ml after the object was added?

chemisty
volume of water delivered using a buret has a mass of 2.67 g. What was the final volume reading on the buret if the inital volume reading was 0.10 ml? [assume the density of water is 1.00g/mL]

chemistry
What is the density of a block of unknown material with a mass of 13.26 g if the dimensions are: length = 2.2 cm height = 1.7 cm width = 4.1 cm

science
What is the density of a block of unknown material with a mass of 13.26 g if the dimensions are: length = 2.2 cm height = 1.7 cm width = 4.1 cm

algebra
a physical education teacher was getting ready for gym class one day . he measured the circumference of the basketball to be 9 inches when it is filled with air . he then went on to pose the following question to his classes : use 3.14 A ) how much material is needed to make f...

physical
A wheel has radius of 0.25 m rotating at 2.08 rad/s. What is the tangential speed of a particle at its edge

physics
thnx

physics
A=2i+3j-k, b=4i=2j-2k, find the vector x parallel to A but has magnitude of B

Physics
A light spiral spring is suspended from its upper end. A mass of 7.5*10^-2, hung from the lower end produces an extension of 0.15 m. The mass is pulled down to a furthur 8.0*10^-2 m and released so that it oscillates calculate the spring constant.

Physics
Sir Steve I got the ans 46 but the correct ans is 48 S=vt+1/2at^2 in 1st gear S=v*2+1/2*20*2^2 S=2v+40..........eq 1 in second gear S=vt+1/2at^2 s=v*2+1/2*40*2^2 S=v+80.........eq 2 in third gear S=vt+1/2at^2 S=v*6=1/2*60*6^2 S=6v+1080.......eq 3 substituting eq 3 in eq 2 we g...

Physics
Sir but the and which u got is the same as i got but its not given in the options. here are the options A. 12 B. 13.3 C. 40 D. 48 E. 37

Physics
14. A racing car accelerates uniformly through three gears, changes with the following average speed: 20 for 2.0 s 40 for 2.0 s 60 for 6.0 s What is the overall average speed of the car?

Physics
14. A racing car accelerates uniformly through three gears, changes with the following average speed: 20 for 2.0 s 40 for 2.0 s 60 for 6.0 s What is the overall average speed of the car?

college physics
A 2000kg van and a 1500 kg car both travelling at 40ms^-1 in opposite directions collide head on and lock together. what are their speed and direction immediately after the collision?

Science
In a tidal barrage scheme, the area of sea-water behind the barrage is 30km^2, tidal depth is 10m and the density of sea water is 1030kgm^-3. a. What energy is possible available from this scheme in one cycle of ebb and flow???

college physics
in a pinball machine, a force of 24 N is used to compress a spring a distance of 0.080m. a. What is the potential energy stored in the spring? b. What is the maximum speed tha it van produve in a ball of mass 0.15kg?

7th Grade Science
U can imagine a syringe filled with gas..... nw assume that ur appying more pressure on it by increasing the pressure on piston.... as ths is done piston moves down thus compressing the volume of gas n hence we say thay volume decreases as piston moves down

physics
Explain how a parachutist's loss of momentum on landing is consistent with the principle of conservation of momentum?

college physics
A water-skier is being pulled at a steady speed in a straight line. her mass plus the mass of the ski is 65 kg. the pull of the tow rope on her is 520 N. a...i) What is the vertical component Y of the push of the water on the ski?? ....ii) What is the horizontal component X of...

physics
A water-skier is being pulled at a steady speed in a straight line. her mass plus the mass of the ski is 65 kg. the pull of the tow rope on her is 520 N. a...i) What is the vertical component Y of the push of the water on the ski?? ....ii) What is the horizontal component X of...

Science
Explain how a parachutist's loss of momentum on landing is consistent with the principle of conservation of momentum?

Science
Thnx a lot steve

Science
A car starts from rest and moves with constant acceleration during the 5th second of its motion,it covers a distance of 36 meters. what is the acceleration

medu
RM 2000 was invested on 15march 2012. If the simple interest rate offered was 10% per annum, find the interest received on 29 August 2012 using A. Exact time and exact simple interest B. Exact time and ordinary simple interest C. Approximate time and exact simple interest D. A...

math
okay

physics
A hose ejects water at a speed of 2m/s through a hole of area 0.01m2.if the water strikes a wall normally,calculate the force on the wall in Newtons,assuming the velocity of water nomal to wall is zero after collision.

poetry
false

poetry
true or false iambic pentameter consists of five feet of two syllables,each of which is an uncaacented syllable followed by an accented one

science
I NEED HELP WITH MY HOMEWORK COULD YOU HELP ME!!!

geometry
reouignerg

biology
at the end of meiosis 2 are the chromosomes replicated?

Accounting-Journal Entry
Cash DR 97500.00 AC Receivable 552500.00 Sales 650000.00 Sales 650000.00 Cost of Sales 390000.00 Gross profit 260000.00

math
a parabolic bridge over a road is 4 meter tall 4 meter wide and 5 meter long determain the maximum height of a 2 meter truck can drive under the bridge

math
Let f be he real-valued function defined by f(x)=sin^3x+sin^3|x| (a) find f'(x) for x>0 (b) find f'(x) for x<0 (c) determine whether f(x) is continuous and x=0 (d) determine whether the derivative of f(x) exists at x=0

2nd Grade
NAME THREE TYPES OF GRAIN GROWN IN PENNSYLVANIA

2nd grade
WHAT ARE THREE TYPES OF GRAIN GROWN IN PENNSYLVANIA

PRODUCT MAP
WHAT ARE THREE TYPES OF GRAIN GROWN IN PENNSYLVANIA

6th grade
what is accleration?

U.S. History
what will be the best thesis to start my paper with? my topic is segregation

Chemistry
Ethylene glycol, HOCH2CH2OH, is used as antifreeze. It is produced from ethylene oxide, C2H4O, by the following reaction. C2H4O(g) + H2O(l) → HOCH2CH2OH(l) Use Hess's law to obtain the enthalpy change for this reaction from the following enthalpy changes. 2 C2H4O(g) ...

Trigonometry
Yes, it is. It's the same answer I got.

biology
What are minerals? Give names of a few minerals and details of the following: 1 Iron and calcium 2 Iodine and phosphorus

university
Market demand for wheat is relatively stable over time but market supply of wheat is very much influenced by the weather. For example, a natural drought decreases the supply of wheat and pushes up its prices while a bumper crop can severely depress wheat prices. Acts of nature...

math
mj:pj (mango juice : pineapple juice) L=liters 8:56-8 (as 8L of pj taken out and 8L of mj added ) 8:48 = 1:6 (1 part of mj 6 part of pj) when 8L taken out of the new mixture this 8L will contain mj:pj = 8*(1/7):8*(6/7)= 8/7:48/7 so 8L of this taken out from original 8-8/7:48-4...

calculus
find the domain and range of the function g(x)= 10+2x-x^2 (all under radical)

7th grade
who is fibnacci

Math
this is so confusing lol mariam xxx

Science 4th grade
I NEED HELP WITH SCIENCE

US History
could i take a test

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