Fuzzyglasses

How many grams of sodium acetate (CH3COO- Na+; Molecular mass= 82g/mole) and how many milliliters of 0.10 M HCl and water must be used in order to prepare 500 mL of a 0.020 M acetate buffer, pH 5.0? the pK of acaetic acid is 4.76.?

I dont remember how to do this! please help!

A dye that is an acid and appears as different colors in its protonated and deprontonated forms can be used as a pH indicator. Suppose that you have a 1.0mM solution of a dye with a pKa of 7.2. From the color, the concentration of the protonated form is found to be 0.00020 M. Assume that the remainder of the dye is in the deprotonated form. What is the pH of the resulting solution?

Can someone please explain this, step by step? I am so confused!! Thanks!

a mass of 3.300 kg sliding along a frictionless floor at 2.5 m/s strikes and compresses a spring of constant k=300 N/m. The spring stops the mass. How far does the mass travel while being slowed by the spring? How long does the mass take to stop?

I dont even remember how to start this problem, or how to do it withou having the acceleration :( please help!!

a boat is tied to a dock ny 4 horizontal ropes. Two ropes, with a tension of 3.80 x 10^2 N each, are at right angles to the dock. Two other ropes, with a tension of 4.30 x 10^2 N each, are at an angle of 20 degrees with the dock. What is the resultant of these two forces?

I've been trying to figure it out using the x and y components and the sine and cosine things, but its just not coming out right! can someone please just explain what the free body diagram would look like, cause im pretty sure thats whats messing me up. Thanks alot!

three rescuers are pulling horizontally on a saftey net to keep it taunt. One pulls northward with a force of 2.80 x 10^2; the second pulls in a direction 15 degrees south of west with a force if 3.20 x 10^2. In which direction, angle, and with what force must the third pull to keep the net stationary?

please help!!!!!!!!!!!!

a boy stands at the edge of a cliff and launches a rock upward at an angle of 45 degrees. The rock comes back down at the elevation where it was released 4.16 seconds later, then continues until it is seen to splash into the lake below 5.91 seconds after release. How far below the point of release is the lake surface? What horizontal distance form the point of release is the splash?

A super ball is thrown to the ground with an initial downward velocity of 1.20 m/s and pops back up to the hand of the thrower; the total time elapsed is .79s. What height was the Super ball thrown?

Sorry, but I completely forgot how to do physics, and I really need help! I tried every equation, and I still cant get the right answer! Please help!

Prove: if a line divides two sides of a triangle so that the corresponding sides are in proportion, then the line is parallel to the third side of the triangle.

Please explain!! Very Confused!! THANKS!!

an inheritance of $12000 is invested in two different mutual funds. one fund pays 5 1/2 % simple interest and the other pays 8% simple interest. write the annual interest y in terms of x.

please help! I kinda have no idea how to do this! Thanks!!

an inheritance of $12000 is invested in two different mutual funds. one fund pays 5 1/2 % simple interest and the other pays 8% simple interest. write the annual interest y in terms of x.

please help! I kinda have no idea how to do this! Thanks!!

how would you find the gram-mass formula of

4Fe(s) + 3O2(g) -> 2Fe2 O3

(the 2 on the 3O2 is a subscript, and the the second 2 and 3 on the 2Fe2 O3 are also subscripts)

Thanks and please explain!! I really have noooo clue how to do this!!

if 20g of ice melts at 0ºC, how much energy does it absorb? If that same 20g of water is changed to vapor at 100ºC, how much energy does it absorb?

Please help!! and show what steps you use to find it please!! Thanks alot!!!!

In a certain school district, the ages of new teachers hired during the last 5 years are normally distributed. Within this curve, 95.4% of the ages, centered about the mean, are between 24.6 and 37.4 years. Find the mean age and the standard diviation of the data.

Please Help!! Really confused!! Thanks a lot!

which transformation best describes the relationship between the functions f(x) = 2^x and g(x) (1 / 2) ^ x ?

(1) reflection over the line y=x

(2)reflection in the orgin

(3) reflection in the x-axis

(4) reflection in the y-axis

please explain!! I have no clue how to do this! thanks!!

if theta is an acute angle such that sine theta = 5 / 13, then what is the value of sin 2theta?

Please explain! I did it out, but I dont think I did it right. Thanks!!

Jamie is designing a storage box in the shape of a cube. Each side of the box has a length of 10 inches. She needs more room and decides to construct a larger box in the shape of a cube with a volume of 2000 cubic inches. By how many inches, to the nearest tenth, should she increase the length of each side of the original box?

I am sooo confused!! PLEASE HELP!! Thank you soooooooo much!!

The lateral surface area of a right circular cone, s, is represented by the equation s = pi(r) sqrt( r^2 + h^2), where r is the radius of the circular base and h is the height of the cone. If the lateral surface area of a large funnel is 236.64 square cm, and its radius is 4.75 cm, find its height, to the nearest hundreth of a cm.

Please help!! Tried this problem, but I cant get the right answer!! please help!!

if f(x) = (3x^2 - 27 ) / (18x + 30) and g(x) = ( x^2 - 7x + 12) / ( 3x^2 - 7x - 20), find f(x) / g(x) for all the values for x where the expression is defined in simplest form.

Please help!!!! PLEASE!! thank you sooo much!

a farmer has a triangular field with sides of 240 feet, 300 feet, and 360 feet. He wants to apply fertilizer to the field. If one 40- pound bag of fertilizer covers 6000 square feet, how many bags must he buy to cover the field?

Please help!! really confused! thank you sooo much!!

A company calculates its profit by finding the difference between revenue and cost. The cost function of producing x hammers is C(x) = 4x +170. If each hammer is sold for $10, the revenue function for selling x hammers is R(x) - 10x.

a) how many hammers must be sold to make a proft?

b) how many hammers must be sold to make a profit of $100?

Please explain how to do this! Im not looking for answers, just explanations!! PLease!! thanks