# SARAH

Popular questions and responses by SARAH
1. ## Physics

A 1000 kg car pushes a 2000 kg truck that has a dead battery. When the drive steps on the accelerator, the drive wheels of the car push against the ground with a force of 4500 N. a) What is the magnitude of the force of the car on the truck? b) what is the

The bases of trapezoid $ABCD$ are $\overline{AB}$ and $\overline{CD}$. We are given that $CD = 8$, $AD = BC = 7$, and $BD = 9$. Find the area of the trapezoid.

3. ## Physics

A grasshopper leaps into the air from the edge of a cliff at a 50 degree angle. He reaches a maximum height 6.74 cm above the top of the cliff and travels a total horizontal distance of 1.06 m. How tall is the cliff and what is the initial speed of the

4. ## Chemistry

Identify the products formed in this Brønsted-Lowry reaction. HPO2−4+HBrO↽−−⇀acid+base Acid: Base:

5. ## physics

It is possible to shoot an arrow at a speed as high as 100 m/s. (a) If friction is neglected, how high would an arrow launched at this speed rise if shot straight up? (b) How long would the arrow be in the air? Please help! I do not have any clue as to how

6. ## Physics

The four tires of an automobile are inflated to an absolute pressure of 2.0*10^5 Pa. Each tire has an area of 0.024m^2 in contact with the ground. Determine the weight of the automobile. Pressure*area= force. There are four tires.

7. ## physics

What is the tension in the rope of this figure description? 60 kg person is hanging in the air on a rope attached to a pulley, with a 100 kg mass attached on other end that is touching the ground.

8. ## Physics

2. Consider the ball example in the introduction when a ball is dropped from 3 meters. After the ball bounces, it raises to a height of 2 meters. The mass of the ball is 0.5 kg a. What is the speed of the ball right before the bounce? b. How much energy

9. ## Physics

A potter’s wheel with rotational inertia of 45 kg m2, is spinning freely at 40 rpm. The potter drops a lump of clay onto the wheel where it sticks a distance 1.2 m from the rotational axis at the wheel’s center. If the subsequent angular speed of the

10. ## History

Which battle was a major turning point for US and South Korean forces during the Korean War? a. Battle of Pork Chop Hill b. Spring Offensive c. Battle of Heartbreak Ridge d. Inchon Bay landing Is it D?

11. ## Physics

A tennis player hits a ball at ground level, giving it an initial velocity of 24 m/s at 57 degrees above the horizontal. (a) what are the horizontal and verticla components of the ball;s initial velocity? (b) how high above the ground does the ball go? (c)

12. ## History

Which accurately describe the causes of the contentious relationship between President Truman and General MacArthur? (Select all that apply.) a. Truman favored a containment policy on Communism, while MacArthur wanted to pursue the Communist forces into

13. ## Calculus!!!

Find f. (Use C for the constant of the first antiderivative and D for the constant of the second antiderivative.) f ''(x) = 8 + x3 + x5

14. ## Physics

The launching mechanism of a toy gun consists of a spring of unknown spring constant, as shown in Figure P5.33a. If its spring is compressed a distance of 0.140 m and the gun fired vertically as shown, the gun can launch a 24.0 g projectile to a maximum

15. ## Physics

a model of a helicopter rotor has four blades, each 3.40 m in length from the central shaft to the tip of the blade. The model is rotated in a wind tunnel at 550 rev/min. A) what is the linear speed, in m/s of the blade tip? B.) what is the radial

16. ## Economics

Questions: Are the following workers more likely to experience short-term or long-term unemployment? Explain. a. A construction worker laid off because of bad weather. b. A manufacturing worker who loses her job at a plant in an isolated area. c. A

17. ## Chemistry

What is the total volume of gases produced at 819 K and 1. atm pressure when 320 g of ammonium nitrite undergoes the following decomposition reaction? NH4NO2 --------> N2(g) + 2H2O(g)

18. ## physics

A certain orthodontist uses a wire brace to align a patient's crooked tooth as in the figure below. The tension in the wire is adjusted to have a magnitude of 21.12 N. Find the magnitude of the net force exerted by the wire on the crooked tooth.

19. ## college physics

three carts of masses 4.0kg, 10kg, and 3.0kg move on a frictionless horizontal track with speeds of 5.0m/s, 3.0m/s, and 4.0m/s. The carts stick together after colliding. find the velocity of the three carts.

20. ## Calculus

The monthly demand function for a product sold by a monopoly is p = 3750 − 1/3x^2 dollars, and the average cost is C = 1000 + 70x + 3x^2 dollars. Production is limited to 1000 units and x is in hundreds of units. (a) Find the quantity that will give

21. ## physics

the speed of the fastest pitched baseball was 45 m/s, and the ball's mass was 145 g. (a) What was the magnitude of the momentum of this ball, and how many joules of kinetic energy did it have? (b) How fast would a 57 gram ball have to travel to have the

22. ## Trig

Cosine theta=8/17 and 270 degrees is < theta, and theta is< 360

23. ## PHYSICAL SCIENCE

A 1.0 kg metal head of a geology hammer strikes a solid rock with a velocity of 5.0 m/s. Assuming all the energy is retained by the hammer head, how much will its temperature increase?

24. ## Calculus

A landscape architect wished to enclose a rectangular garden on one side by a brick wall costing $60/ft and on the other three sides by a metal fence costing$50/ft. If the area of the garden is 102 square feet, find the dimensions of the garden that

25. ## math

A recipe that makes 18 cookies calls for 3/4 cup of sugar. How much sugar is needed to make 24 cookies using this recipe?

26. ## Physics

When a driver applies brakes to keep a car going downhill at constant speed and constant kinetic energy, the potential energy of the car decreases. Where does this energy go? Where does most of it appear in a hybrid vehicle?

27. ## phyics

Cheryl is riding on the edge of a merry-go-round, 2m from the center, which is rotating with an increasing angular speed. Cheryl’s tangential acceleration is 3.0m/s2. At the instant that Cheryl’s linear speed is 4.0m/s, what is Cheryl’s total

28. ## english

Which of the following is the best definition of a drama? a. a story with props b. a story with a happy ending c. a story written to be preformed by actors d. a story in which the main character eventually fails I think it's D, can anyone check me? Thanks

29. ## math

Convert the base-ten number to a numeral in the indicated base. 329 to base six

30. ## Mathematics

A closed tin of milk has diameter 10cm and height 16cm find the total surface area of the tin( take pie to be 22/7

31. ## biology

Which best describes Francis Bacon’s contribution to the Scientific Revolution?

32. ## PHYSICS

A 200g block slides back and forth on a frictionless surface between two springs, as shown. The left-hand spring has k = 130 N/m and its maximum compression is 16cm. The right-hand spring has k = 280 N/m. Find (a) the maximum compression of the right-hand

33. ## math

seven horses are entered in a race. If two horses are tied for first​ place, and there are no ties among the other five ​horses, in how many ways can the seven horses cross the finish​ line?

51. ## Enthalypy Reaction

What is the standard enthalpy of reaction for the following chemical reaction? CO2(g) + 2KOH(s) --> H2O(g) + K2CO3 (s) Express your answers numerically in kJ.

52. ## chemistry

What is the mass of 225ml of a liquid that has a density of 0.880g/ml

Suppose the moon rotated on its axis just as quickly as Earth. Would you still always see the same side of the moon from Earth? *HELP ME PLEASE*

54. ## probability

For a family with 2 children, the sample space indicating boy (B) or girl (G) is BB, BG, GB, and GG. If each of the outcomes is equally likely, find the probability that the family has 2 girls, given that the first child is a girl.

55. ## World Geography

Imagine you are an elected official with the responsibility of drafting legislation designed to protect our environment. What items will you include in your bill? Who will be responsible for the bill's implementation? Its enforcement? Your response should

56. ## Chemistry

What is the value of q when 8.21g of water vaporizes at 373 K? The enthalpy of condensation of water at 373 K is -40.7 kJ/mol. I tried using the equation q= m x Cs x Delta T, but I never got the right answer which is 18.5 kJ apparently, so I need to find

57. ## Chemistry 20

which of the following indicators would show an intermediate endpoint of color of orange: bromocresol green, methyl red, phenolphthalein or methyl violet? No clue how to do this. And what does it mean to show an intermediate endpoint. Please help

58. ## Civics

1. Suppose Bill HR612 is currently in Congress. One thing you know about this bill is that it A. originated in the House of Representatives. B. has been vetoed by the president. C. has no riders attached. D. is currently in committee. A?

59. ## math

In a certain town, 25% of people commute to work by bicycle. If a person is selected randomly from the town, what are the odds against selecting someone who commutes by bibycle? A). 3:1 B). 3:4 C). 1:3 D). 4:1

60. ## chemistry

Nucleophile or electrophile? (1) CH3COOH (2) CH3COO- At first, I thought that they were both Nucleophiles, but now Ive confused myself and Im not sure.. Please help!

61. ## Chemistry

The thermal decomposition of 1.6608 g of MgSO4 * H2O produces 1.4446 g of a product in a well-behaved reaction. There are two possibilities: 1) MgSO4 * H2O(s) -> MgSO4(s) + H2O(g) 2) MgSO4 * H2O(s) -> MgO(s) + SO3(g) + H2O(g) Complete the following table,

62. ## Chem

Consider the following balanced equation: 2N2H4(g)+N2O4(g)→3N2(g)+4H2O(g) Complete the following table showing the appropriate number of moles of reactants and products. If the number of moles of a reactant is provided, fill in the required amount of the

63. ## Civics

6. If both the president and the vice president are unable to fulfill their duties, who takes over as president? A. President pro tempore of the Senate B. Attorney general C. Speaker of the House D. Secretary of state "In the case that the president can no

64. ## finance

A firm has beginning inventory of 300 units at a cost of $11 each. Production during the period was 650 units at$12 each. If sales were 700 units, what is the cost of goods sold (assume FIFO)?

65. ## Physics

The speed of sound in steel is 5000 m/s. What is the wavelength of the sound wave of 640 Hz in steel?

66. ## Physics

a 65-kg ice skater moving to the right with a velocity of 2.50m/s throws a .150kg snowball to the right with a velocity of 32.0m/s relative to the ground a) what is the velocity of the ice skater after throwing the snowball? b) a second skater initially at

Consider the freight train. Suppose 15 boxcars pass by in a time of 14.0 s and each has a length of 14.0 m. (a) What is the frequency at which each boxcar passes? (b) What is the speed of the train?

68. ## science

How many neutrons does the most common isotope of carbon contain? Use the diagram below to help you.

69. ## Calc

If y=tanu, u=v-(1/v), and v=lnx. What is the value of dy/dx at x=e?

70. ## Physics

A diver leaves a 3-m board on a trajectory that takes her 2.8m above the board and then into the water 2.7m horizontally from the end of the board.At what speed and angle did she leave the board?

71. ## Chemistry

Which one of the following liquids will have the highest freezing point? A. pure H2O B. aqueous glucose (0.050 m) C. aqueous CoI2 (0.030 m) D. aqueous FeCl3 (0.030 m) E. aqueous NaI (0.030 m) Could you please give a step by step process?

72. ## Calc.

Please help solve this, A farmer has 600m of fence and wants to enclose a rectangular field beside a river. Determine the dimensions of the fence field in which the maximum area is enclosed. (Fencing s required on only three sides: those that aren't next

73. ## Partial Pressure- Chemistry

A gaseous mixture of O2 and N2 contains 31.8 % nitrogen by mass. What is the partial pressure of oxygen in the mixture if the total pressure is 445 mmHg?

74. ## Algebra

A chemist wishes to mix a solution that is 4​% acid. She has on hand 66 liters of a 2​% acid solution and wishes to add some 8​% acid solution to obtain the desired 4​% acid solution. How much 8​% acid solution should she​ add? There is a chart

75. ## Biology

Is 9th grade biology hard? Is it interesting...?? I love life science but I just wondering if 9th grade biology hard??? I'm taking biology next year.

76. ## physics

an experimental rocket plane lands on skids on a dry lake bed. it is traveling at 80.0 m/s when it touches down, how far does it slide before it comes to a stop? assume the coeffcient of kinetic friction between the skids and the lake is .600

77. ## Physics

In the figure, a chain consisting of five links, each of mass 0.100 kg, is lifted vertically with constant acceleration of magnitude a = 2.50 m/s2. Find the magnitudes of (a) the force on link 1 from link 2, (b) the force on link 2 from link 3, (c) the

78. ## Physics

A bowling ball weighing 71.2 N is attached to the ceiling by a 3.80 m rope. The ball is pulled to one side and released; it then swings back and forth like a pedulum. as the rope swings through its lowest point, the speed of the bowling ball is measured at

79. ## Physics

A Chinook salmon can jump out of water with a speed of 6.60 m/s . How far horizontally d can a Chinook salmon travel through the air if it leaves the water with an initial angle of θ=27.0° with respect to the horizontal? (Let the horizontal direction the

80. ## Chemistry

From the lewis structure of AlCl4- where should I place the formal charge? next to Al or Cl?

81. ## Physics

A bullet of mass 45 g is shot at a speed of 220 m/s into a 5.0-kg bag hanging from a string from the ceiling. The bag absorbs the bullet and begins to swing. To what maximum vertical height will it rise? Hint: Energy is not conserved as the bullet enters

82. ## Chemistry

The reaction of aqueous sodium bromide and aqueous lead(II) nitrate is represented by the balanced net ionic equation. 2Br-(aq) + Pb2+(aq) → PbBr2(s) Give the balanced ionic equation for the reaction. Include the states.

91. ## Chemistry

Write a net ionic equation for the reaction that occurs when excess hydrobromic acid (aq) and sodium sulfide are combined.

92. ## English

Roosevelt is arguing that journalists must only attack misconduct when they have valid proof. They must not dig just for the sake of digging; it is offensive to good Americans. Which statement most effectively argues against this claim? a) Even sensational

93. ## Drama

In act 1 scene 2 of a christmas carol scrooge and marley, why does scrooge object to people enjoying christmas?

94. ## Math

A drawer contains 22 black socks, 22 white socks, and 22 blue socks. If the light is off and Matt reaches into the drawer to get his socks, what is the minimum number of socks he must pull out in order to be sure that he has a matching pair?

95. ## Physics

A track star in the long jump goes into the jump at 12 m/s and launches herself at 20.0° above the horizontal. How long is she in the air before returning to Earth? (g = 9.81 m/s2)

96. ## Math(problem solving)

Four darts are thrown at this dartboard. If all four darts hit the board, how many different point totals are possible? there are 4 circles with point totals: working out from the middle bulls eye.. bulls eye = 9 2nd circle = 7 3rd circle = 4 outter circle

97. ## microeconomics

1. Market demand is given as QD = 250 – 0.5P. Market supply is given as QS = 2P. In a perfectly competitive equilibrium, what will be the value of consumer surplus? a.$10 000 b.$20 000 c.$40 000 d.$80 000 2. Market demand is given as QD = 250 – 0.5P.

98. ## chemistry

Calculate the concentration of oxalate ion (C2O42−) in a 0.175 M solution of oxalic acid (C2H2O4). [For oxalic acid, Ka1 = 6.5 × 10−2, Ka2 = 6.1 × 10-5.]