# Annika

1. ## Chemistry Help

For the reaction 2HI(g) H2(g) + I2(g), Kc = 0.0198 at 721K. What is the HI concentration at 721K if [H2] = 0.120 M and [I2] = 0.0150 M? I'm getting .303 M but that's not one of the options.
2. ## Math

A car travels 168.75 km in 12.5 litres of petrol . Find the distance travelled by the car in 15 litres
3. ## Math

Solve and prove the identity (tan x+ cot (-x))/ (tan x - cot(-x))= 1-2cos^2(x)
4. ## Math

A rectangle made of square tiles measures 8 tiles wide and 10 tiles long. What is the length in tiles of a similar rectangle 12 tiles wide?
5. ## math

two joggers used a 2 km circular road for their training. if they start together from the same place and jog in opposite directions, they meet after 15 minutes. However, if they jog in the same direction at the end of one hour and 15 minutes, the faster
6. ## Science

1. A pea plant with yellow seeds is crossed with a pea plant with green seeds. All of the offspring have yellow seeds. The allele for yellow seeds is A. dominant because all of the offspring has yellow seeds** B. recessive because all of the offspring has
7. ## Math

Express the following as a logarithm and simplify. 1. log(3x^2 + 11x - 20) - log(3x - 4) 2. 1/6 log3 27 + log3 18 - log3 2 3. log5 cube root of 625 4. 2loga x^3 + 3loga y + 4loga z - 3logz w
8. ## Math

Express the following as a logarithm and simplify. 1. log(3x^2 + 11x - 20) - log(3x - 4) 2. 1/6 log3 27 + log3 18 - log3 2 3. log5 cube root of 625 4. 2loga x^3 + 3loga y + 4loga z - 3logz w
9. ## Math

Why is zero not in the doamin of the logarithmic functions y= log3 x and y = log5 x?
10. ## Physics

1. Give 3 reasons why it is important to know the nature and properties of waves. 2. Aside from crossing the street, identify one scenario in practicing road safety and explain how it is realted to Doppler Effect.
11. ## Math

If the graph is decreasing from left to right, which of the following equations may be represented by it. 1. y = 2^x + 1 2. y = -2^-x + 1 3. y = 2^-x – 1 4. y = 2^-x + 1
12. ## Math

A rectangular lawn is 60meters by 80meters. A part of the lawn is torn out to install a pool, leaving a strip of lawn of uniform width around the pool. The area of the poolnis 1/6 of the old lawn area. How wide is the strip of lawn?
13. ## Math

A gardenervhas 100 meters of fencing to enclose two adjacent rectangular gardens. The gardener wants the enclosed area to be 400 sq meters. What dimensions should the gardener use to obtain this area?
14. ## Math

1. A gardener has 30 feet by 20 feet rectangular plot of ground. He wants to build a brick of walkway of uniform width on the border of the plot. If the gardener wants to have 400 square feet of ground left for planting, how wide should he build the
15. ## Math

1. The quadratic equation -3x^2 – x = 10 has two real solutions. (true or False) Justify your answer. 2. If (2x – 3) (x + 5) = 8, then either 2x – 3 = 8 or x + 5 = 8. (True or False) Justify your answer.
16. ## Physics

We have a projectile launched upward with an initial horizontal velocity of 20 m/s and an initial vertical velocity of 30 m/s. 1. What is the actual initial speed of the projectile? 2. What happens to the horizontal component of the velocity as the
17. ## Math

Encircle the error in the following "proof" that the two arbitrary numbers are equal to each other. Let a and b the arbitrary numbers such that a is not equal to b. Then, (a - b)^2 = a^2 - 2ab + b^2 = b^2 - 2ab + a^2 (a - b)^2 = (b - a)^2 a - b = b - a 2a
18. ## Math

Consider the general quadratic equation ax^2 + bx + c = 0, where a is not equal to 0. Solve for x by completing the square.
19. ## Math

Find the 12th term of the arithmetic sequence 2, 6, 10, … .
20. ## Math

Solve for the 101st term of the sequence whose 1st term is x-y and d=2x+y-3.
21. ## Math

1. Find the 12th term of the arithmetic sequence 2, 6, 10, … . 2. Solve for the 101st term of the sequence whose 1st term is x-y and d=2x+y-3. 3. In the sequence 2, 6, 10, … , what term has a value of 106?
22. ## Math

Solve for the 101st term of the sequence: 6-p, 4+p, 2+3p, 5p, … .
23. ## Math

Solve for the 1st term of the arithmetic sequence whose 33rd term is -2p and whose 61st term is 26p.
24. ## Math

Find one solution for each equation. 1. cos 4theta = sin theta 2. tan 4theta = cot (20^0 + 20) Write the function sin (B + 35^0) in terms of its cofunction.
25. ## math - trig

Suppose ABC is a right triangle with sides of lengths a, b, and c and right angle at C. Find the unknown side length using the Pythagorean Theorem and find the following trigonometric functions of the indicated angle. Given: a = 4 and b = 7 Find: sin A,
26. ## Science-Chemistry

List materials that are commonly found at home or in school that have: a. Different structures and exhibit different properties b. The same chemical make-up (composition) but with different structures, hence, different properties c. The same properties but
27. ## Science - Chemistr++++++++++++++++++++++++++++++++

List materials that are commonly found at home or in school that have: a. Different structures and exhibit different properties b. The same chemical make-up (composition) but with different structures, hence, different properties c. The same properties but
28. ## science

The atomic mass of lithium is 6.94, the naturally occurring isotopes are 6Li = 6.015121 amu, and 7Li = 7.016003 amu. Determine the percent abundance of each isotope.
29. ## math - trig

1. Find csc A, cos A and tan A of an angle A whose terminal side contains (– 12, – 5). 2. Find sin X, sec X and cot X of an angle X whose terminal side contains (– 3, 5).
30. ## Math

What is the measure of the side of a cube if the volume is 27000cm3?
31. ## Math

A rectangular prism has a volume of 960cm. It's width, length, and height are in the ratio 3:5:8. A) Determine the dimensions of the prism B) What is the ratio of the left side to the front to the top of the prism by surface area? C) Calculate the surface
32. ## physics

Star Z has 1/5 the radius of Earth and 1000 times the Earth's mass. If a mass weighs 1.0 N on Earth, what does it weight on Star Z?
33. ## physics

Star Z has 1/5 the radius of Earth and 1000 times the Earth's mass. If a mass weighs 1.0 N on Earth, what does it weight on Star Z?
34. ## horoscopes

on which site can you find out about all the new horoscopes 2009?
35. ## english word

If 'quartered' means the object has been divided into four, which word do we use for an object that's been divided into 5?
36. ## english

I'm trying to study satire. I found this poem online Now if you take an orange And hold it in your hand, It isn't really there at all - Or so I understand. A sensationalist will prove to you That though you know it's there, It's only just sensations Of
37. ## English

I have to write a concise precis of a short story that I read, consisting of 130 words. What is a 'precis'?