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February 1, 2015

Posts by Sierra


Total # Posts: 239

Physics
An ice cube of volume 17.7 cm3 is initially at a temperature of -19.3°C. How much heat is required to convert this ice cube into steam?
July 31, 2012

Physics
How much heat is required to raise the temperature of a 4.3-kg block of steel by 48 K? (The specific heat of this steel is 450 J/kg · K.)
July 31, 2012

Physics
A tank of water sits at the edge of a table of height 1.4 m. The tank springs a very small leak at its base, and water sprays out a distance of 1.2 m from the edge of the table. What is the water level h in the tank? (Assume the tank is open to the air at the top.)
July 25, 2012

Physics
Water is flowing through a pipe (area 4.0 cm2) that connects to a faucet adjusted to have an opening of 0.57 cm2. If the water is flowing at a speed of 5.3 m/s in the pipe, how long does it take for water from the faucet to fill a bucket of volume 0.11 m3?
July 25, 2012

Physics
Two metal blocks are attached by a cable as shown in the figure below and are submerged at rest near the surface of a lake. If the volumes are V1 = 2.1 m3 and V2 = 1.1 m3, what is the total buoyant force on the two blocks?
July 25, 2012

Physics
You want to design a helium-filled balloon that will lift a total payload of 1225 kg. What volume of helium is needed to just barely lift this payload?
July 25, 2012

Physics
A block of mass 20 g sits at rest on a plate that is at the top of the fluid on one side of a U-tube as shown below. The U-tube contains two different fluids with densities ρ1 = 965 kg/m3 and ρ2 = 550 kg/m3 and has a cross sectional area A = 5.5 10-4 m2. The surfaces...
July 25, 2012

Physics
A syringe has an area of 1.4 cm2 at its barrel and then narrows down to an area of 0.08 mm2 at the needle end. If a force of 5.5 N is applied to the syringe, what is the force produced at the tip of the needle?
July 25, 2012

Physics
A bucket is filled with a combination of water (density 1,000 kg/m3) and oil (density 700 kg/m3). These fluids do not mix. (The oil will float on top of the water.) If the layer of oil is 63 cm tall, what is the pressure at the interface between the oil and the water?
July 25, 2012

Physics
A U-tube contains two fluids with densities ρ1 = 1070 kg/m3 and ρ2 = 595 kg/m3 as sketched below. What is the difference d in the heights of the top surfaces of the two fluids?
July 25, 2012

Microbiology
What responsibilities do patents have for their children's health?
July 15, 2012

trig
Solve the equation on the interval [0,360) cos^2t+2cos(t)+1=0
July 12, 2012

trig
Find all solutions in the interval [0,360) sin(4t)=ã3/2
July 12, 2012

Physics
Nothing
July 11, 2012

physics
You are pushing a refrigerator across the floor of your kitchen. You exert a horizontal force of 273 N for 7.2 s, during which time the refrigerator moves a distance of 3.4 m at constant velocity.
July 11, 2012

Physics
A rock of mass 0.086 kg is thrown upward with an initial speed of 13 m/s. Find the work done by gravity on the rock from the time it leaves the thrower's hand until it reaches the highest point on its trajectory. Hint: You do not have to calculate the rock's maximum ...
July 11, 2012

Physics
A car of mass 1,700 kg is initially traveling at a speed of 25 m/s. The driver then accelerates to a speed of 35 m/s over a distance of 500 m. Calculate the change in the kinetic energy of the car.
July 11, 2012

Physics
A car of mass 1,700 kg is initially traveling at a speed of 25 m/s. The driver then accelerates to a speed of 35 m/s over a distance of 500 m. Calculate the change in the kinetic energy of the car.
July 11, 2012

Physics
A block of mass is pulled along a rough horizontal surface by a rope as sketched in the figure below. The tension in the rope is 45 N, and the coefficient of kinetic friction between the block and the surface is
July 11, 2012

Physics
A crate of mass 29 kg is pushed up a ramp by a person as shown in the figure below. The person pushes the crate a distance of 25 m as measured along the ramp. Assume the crate moves at constant velocity. Assume the coefficient of kinetic friction between the crate and the ramp...
July 11, 2012

Physics
A crate of mass 59 kg is pushed across a level floor by a person. If the person exerts a force of 30 N in the horizontal direction and moves the crate a distance of 12 m, what is the work done by the person?
July 11, 2012

English
i can not seem to find who the Fictional Character Justice Johnson is, i dont even see it anywhere in my book?
July 10, 2012

Physics
A sphere of mass 85 kg is attached to one end of a rope as shown in the figure below. It is found that the rope does an amount of work W = 8030 J in pulling the sphere upward through a distance 9.6 m. Find the tension in the rope.
July 6, 2012

Physics
Speed of a satellite orbit (physics problem)? What is the speed of a satellite in a geosynchronous orbit about Earth? _________m/s Compare it with the speed of the Earth as it orbits the Sun. _________m/s
June 29, 2012

Physics
In recent years, a number of nearby stars have been found to possess planets. Suppose, the orbital radius of such a planet is found to be 3.0 1011 m, with a period of 1000 days. Find the mass of the star.
June 29, 2012

Physics
Saturn makes one complete orbit of the Sun every 29.4 years. Calculate the radius of the orbit of Saturn. Hint: It is a very good approximation to assume this orbit is circular.
June 29, 2012

Physics
A stone of mass 0.31 kg is tied to a string of length 0.65 m and is swung in a horizontal circle with speed v. The string has a breaking-point force of 70 N. What is the largest value v can have without the string breaking?
June 29, 2012

Physics
Consider points on the Earth's surface as sketched in the figure below. Because of the Earth's rotation, these points undergo uniform circular motion. Compute the centripetal acceleration at the following points.
June 29, 2012

Physics
Suppose the circular track in the figure below has a radius of 104 m and the runner has a speed of 3.3 m/s.
June 29, 2012

Physics
Suppose the circular track in the figure below has a radius of 104 m and the runner has a speed of 3.3 m/s.
June 29, 2012

Physics
A jogger is running around a circular track of circumference 480 m. If the jogger has a speed of 11 km/h, what is the magnitude of the centripetal acceleration of the jogger?
June 28, 2012

Physics
Mars has two moons, Phobos and Deimos. It is known that the larger moon, Phobos, has an orbital radius of 9.4 106 m and a mass of 1.1 1016 kg. Find its orbital period.
June 25, 2012

Physics
Uranus makes one complete orbit of the Sun every 83.8 years. Calculate the radius of the orbit of Uranus. Hint: It is a very good approximation to assume this orbit is circular.
June 25, 2012

Physics
The region of the solar system between Mars and Jupiter contains many asteroids that orbit the Sun. Consider an asteroid in a circular orbit of radius 4.3 1011 m. Find the period of the orbit.
June 25, 2012

Physics
Find the gravitational force of the Sun on Jupiter.
June 25, 2012

Physics
The track near the top of your favorite roller coaster has a circular shape with a diameter of 36 m. When you are at the top, you feel as if you weigh only one-fifth of your weight on the ground. What is the speed of the roller coaster?
June 25, 2012

Physics
The track near the top of your favorite roller coaster has a circular shape with a diameter of 36 m. When you are at the top, you feel as if you weigh only one-fifth of your weight on the ground. What is the speed of the roller coaster?
June 25, 2012

Physics
What is the minimum speed the rock can have without the string becoming "slack"? (The rock is traveling in vertical circle. Assume that m = 1.6 kg and r = 0.48 m.)
June 22, 2012

Physics
Consider the motion of the rock in the figure below. What is the minimum speed the rock can have without the string becoming "slack"? (The rock is traveling in vertical circle. Assume that m = 1.6 kg and r = 0.48 m.)
June 22, 2012

Physics
A bicycle wheel of radius 0.2 m is spinning at a rate of 70 revolutions per minute.
June 22, 2012

Physics
A soccer ball is kicked with an initial speed of 27 m/s at an angle of 20° with respect to the horizontal. A) find the maximum height reached by the ball. B) find the speed of the ball when it is at the highest point on its trajectory. C) where does the ball land? That is ...
June 20, 2012

Physics
A soccer ball is kicked with an initial speed of 27 m/s at an angle of 20° with respect to the horizontal.
June 20, 2012

Physics
A quarterback is asked to throw a football to a receiver that is 32.6 m away. What is the minimum speed that the football must have when it leaves the quarterback's hand? Ignore air resistance. Assume the ball is caught at the same height as it is thrown.
June 20, 2012

Physics
A cable attached to a block of mass 8 kg pulls the block along a horizontal floor at a constant velocity. If the tension in the cable is 5.3 N, what is the coefficient of kinetic friction between the block and the floor?
June 20, 2012

Physics
Two children are playing on a 154-m-tall bridge. One child drops a rock (initial velocity zero) at t = 0. The other waits 1.1 s and then throws a rock downward with an initial speed v0. If the two rocks hit the ground at the same time, what is v0
June 20, 2012

Physics
A squirrel is resting in a tall tree when it slips from a branch that is 43 m above the ground. It is a very agile squirrel and manages to land safely on another branch after only 0.47 s. What is the height of the branch it lands on?
June 20, 2012

social studies
what is one important difference between the koreas and japan 1)korea has may mountains 2)japan is not crowded but korea is 3)the korean peninsula is on stable ground 4)koreas mineral resources are used and japans are not
March 16, 2012

physics
A cube of lead measuring 1 meter on each side is thrown into the ocean. Determine the buoyant force acting on this mass of lead. The density of lead is 11.4 grams/ cubic centimeter
March 8, 2012

physics
The pressure under the surface of a liquid increases with depth. Determine the pressure in Newtons per square meter on a lake at a depth of 100 meters (over 300 feet).
March 8, 2012

algebra
can you simplify Simplify 5m - 13n - n + 4m
February 16, 2012

Civics
i have no book!
February 15, 2012

Civics
Well is it number 3?
February 15, 2012

Civics
Which statement about the relationship between the president and the Cabinet is false? =Because the president is so busy, members of the Cabinet often have a good deal of leeway in the running of their departments. Not all executive departments are subject to presidential ...
February 15, 2012

Civics
Article II of the United States Constitution established the _____. presidency only presidency and the vice presidency the vice presidency only =the Senate and the House
February 14, 2012

Civics
Since the 1970s, the Supreme Court has interpreted the Equal Protection Clause as prohibiting the government from making "_____" distinctions between people. unreasonable =racial reasonable unnecessary
February 14, 2012

American Government
There is stuff about alabama. "I have a dream that one day, down in Alabama, with its vicious racists, with its governor having his lips dripping with the words of interposition and nullification; one day right there in Alabama, little black boys and black girls will be ...
February 14, 2012

American Government
Which statement does NOT characterize Martin Luther King Jr.'s "I Have a Dream" speech? 1.)It openly criticized the Governor of Alabama 2.)It supported the peaceful congregation of peoples of all races and religions 3.)It pointed out racial problems in the South ...
February 14, 2012

Civics
Which is NOT true of the segregation laws passed after the Civil War? =They prohibited interracial marriage. They did not only apply to blacks. They were only in the South. All of these statements are true.
February 14, 2012

Civics
The Constitution gives sovereignty only to the _____.? A.State legislatures B.national government C.president of the United States D.State constitutions ....i need help, none of them are right?
February 14, 2012

civics
_____ States supported the _____ Plan, which called for a bicameral legislature in which States would be represented according to their population. Slave, Three-Fifths =Larger, Virginia Northern, Connecticut Smaller, New Jersey
February 14, 2012

Civics
Which of the following was NOT a reason why a stronger central government was needed? To solve the economic problems of the United States =To limit individual liberties To deal with military matters both internal and external To make the States work together as a single ...
February 14, 2012

science
What materials can I use to make an imprint like a fossil?
January 23, 2012

Science
Suppose you find a fossil imprint of an animal that existed many years ago.How can I make a model to compare that imprint to the foot of an animal living today?
January 23, 2012

Civics
Then is it number 3?
January 20, 2012

Civics
Which is NOT a responsibility of the Department of Agriculture? 1. The opening of foreign markets to U.S. agricultural products =2. To oversee federal anti-hunger programs 3. The designation of lands for private and public use 4. Support for farmers with agricultural research
January 20, 2012

art
what is the definition of pattern, in elements of design
December 11, 2011

spanish
how do you say, "what subjects are at your school.?"
December 1, 2011

statistics
Determine the sample size needed in order to be 95 percent confident the p, the sample proportion of HD television sets that last at least five years without a single repair, is within 0.03 of , the true proportion of sets that last at least five years without a single...
November 28, 2011

sciene
how do u research speeches on the internet {worldbiomes}.
November 8, 2011

Algebra
In solving the equation (x + 3)(x + 1) = 48, Eric stated that the solution would be x + 3 = 48 => x = 45 or (x + 1) = 48 => x = 47 However, at least one of these solutions fails to work when substituted back into the original equation. Why is that? Please help Eric to ...
October 13, 2011

Science
A football player has to push a blocking sled the length of a football field. What are two ways the workload for the football player could be increased?
October 11, 2011

Physics 6A
shortcut: \hat
September 21, 2011

Physics
In recent years, a number of nearby stars have been found to possess planets. Suppose, the orbital radius of such a planet is found to be 3.0 1011 m, with a period of 1000 days. Find the mass of the star.
September 20, 2011

math
I can't figure this out this problem.. estimate 20% of 131 by using 10%
May 30, 2011

Calculus 12 Optimization
120
May 19, 2011

calculus
Find f^-1(13), f(x)= 2x^5 + 3x^3 + 8x and find D(f^-1(x)) at x=13. Is this correct... I got 1/27 ??
March 22, 2011

Chemistry
What is the pH of a solution that is comprised of 0.0843 M HCl and 0.0287 M HClO4?
March 7, 2011

Chemistry
aqueous sulfurous acid H2SO3 was made by dissolving 0.200 L of sulfur dioxide gas at 19 C and 745 mm Hg in water to yield 500.0 ml of solution. the acid solution required 12.9 ml of sodium hydroxide solution to reach the titration end point. what was the molarity of the sodium...
February 20, 2011

Chemistry
What is the volume of Tin(Sn)? Mass of sample = 2.588g Initial vol. of water = 31 m/L Final vol. of water = 32 m/L
February 10, 2011

physics
A damped mass-spring system oscillates at 190 Hz. The time constant of the system is 2.0 s. At t = 0, the amplitude of oscillation is 6.5 cm and the energy of the oscillating system is then 65 J. (a) What is the amplitude of oscillation at t = 2.0 s? What is the amplitude at t...
January 31, 2011

physics
The 2 kg block in Figure 7-25 slides down a frictionless curved ramp, starting from rest at a height of h = 3 m. The block then slides d = 12 m on a rough horizontal surface before coming to rest. Figure 7-25 (a) What is the speed of the block at the bottom of the ramp? (b) ...
January 30, 2011

Math
Determine whether the function is periodic. State the period, the domain and the range of g(x)= 2 cos 2x+3 sin 5x
January 26, 2011

math
a boring job
January 24, 2011

Physics
A person of mass 55 kg stands at the center of a rotating merry-go-round platform of radius 3.4 m and moment of inertia 670 kg·m2. The platform rotates without friction with angular velocity 1.0 rad/s. The person walks radially to the edge of the platform. (a) Calculate...
January 23, 2011

Physics
If I have an originaloscilation frequency of .64 and amplitued of 15 What would doubling the mass of the object do to the freqency and amplitude?
January 22, 2011

Math
If you are given a problem that has measurements in yards and asks you to find surface area, what would the units be in your answer?
January 19, 2011

social studies
6. Stabilization policies can best be described as policies that: A. attempt to eliminate recession and/or inflation in the economy. B. use changes in government spending to promote an equitable income distribution. C. use changes in the money supply to lower income tax ...
January 17, 2011

physics 11
if you have the formula W=Fd, where W=work, F=force, and d=displacement, how do you find W if you don't have F, but you have a mass and displacement?
January 11, 2011

physics 11
brutus, a champion weightlifter, raises 240 kg a distance of 2.35 m. How much work is done by Brutus lifting the weights?
January 11, 2011

Organic Chemistry
A student wanted to synthesize the anesthetic 2-ethoxy-2-methylpropane. She used ethoxide ion and 2-chloro-2-methylpropane for the synthesis and ended up with little of the desired product. Why? What major product did she obtain? What reagents should she have used?
November 21, 2010

AP Physics
there are two vectors in quadrant three one with a magnitude of 31.0N and has a direction of 117degrees in the negative direction from the x axis the other has an unknown magnitude and unkown theta in the positive direction starting from 90 degrees Find the scalar product of ...
November 21, 2010

AP Physics
there are two vectors in quadrant three one with a magnitude of 31.0N and has a direction of 117degrees in the negative direction from the x axis the other has an unknown magnitude and unkown theta in the positive direction starting from 90 degrees
November 21, 2010

AP Physics
Find the scalar product of the vectors in Figure P7.8, where è = 117° and F = 31.0 N. y | | ___| Unk Angle----> / | -------\--------------x starts@O-----> / /| / / /_|/<-----117 degrees / / | / / <-----31.0N
November 21, 2010

AP Physics
A basketball player makes a jump shot. The 0.700-kg ball is released at a height of 2.00 m above the floor with a speed of 7.70 m/s. The ball goes through the net 3.00 m above the floor at a speed of 3.10 m/s. What is the work done on the ball by air resistance, a ...
November 21, 2010

6 grade algebra
cindy earns 6% simple interest each year on her savings account. if she has $850 in her account and leaves the money in there for 5 years. how much interest will the money earn? what is the new balance in cind's account?
November 12, 2010

Chemsitry
Calculate the weight of KHP that will react with 25mL of .1M NaOH
October 19, 2010

math
x/5-1=3
September 22, 2010

Chemistry
(1.48 cg) + (0.347 g) . Answer in units of g
April 1, 2010

college
Solve the inequality using a sign graph (test point method) x^3-x^2-4x+4<0
March 17, 2010

diagramming a sentence
In this sentence, "Yellowstone National Park is in Wyoming", is the word "in" the present tense verb?
January 14, 2010

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