# Posts by tom

Total # Posts: 1,421

**maths**

Express sin 2x cos 4x as a sum of trigonometric functions

**maths stats**

For each day of the 5-day working week Tom can choose any one of 6 newspapers to read at the lunchtime. (i) How many different choices are possible in a week? (ii) If Tom wants to read a different title each day, then how many different choices are possible in a week?

**Physics**

Amy age 8 27kg 127cm Bruce age 12 41kg 149cm Both Amy and Bruce are learning gymnastics and having trouble being able to get enough height and time in the air to do a back somersault without the coach spotting them. The coach gives them homework to just focus on jumping ...

**math problem**

To make an orange dye, 4 parts of red dye are mixed with 3 parts of yellow dye. To make a green dye, 2 parts of blue dye are mixed with 1 part of yellow dye. If equal amounts of green dye and orange dye are mixed,___________ of this mixture is composed of yellow dye.

**math**

According to the statistics of a famous high school in Canada, all their graduates went to either A or B for university study. Following are the proportions of graduates who went to the two universities. University Proportion A 1-k B k Suppose k = 0.4 (a) What is the standard ...

**Algebra 1**

Mr. Jones got his car washed at super clean. The wash started at 1:55pm and ended at 2:05pm. It cost $7. Mr. Smith got his car washed at Super Clean for $12. the wash started at 9:30am and ended at 9:50 am. Write an equation for the line that represents this situation. Part 2...

**programming**

There are several types of room in a hotel. The HotelRoom Class of Previous Programming Problem was not specific regarding the type of room. Assume that a hotel has guest rooms and meeting rooms. Modify the HotelRoom class as follows: remove the capacity and status instance ...

**Physics**

A 2.50 kg wheel has a diameter of 20.0 cm and is rotating at 3600 rpm. A force acts on it causing it to come to a rest in 10.0 seconds. What is the magnitude of the force?

**Chemistry**

No problem :)

**Chemistry**

For the online course, 1)b and 2)c

**eng**

is the sentence: "By using a statement that began with 'I,' Ramon was able to state his feelings clearly." a simple sentence or a complex sentence?

**Physics HELP!**

The position of an object connected to a spring varies with time according to the expression x = (7.1 cm) sin (2.1π t). Find (a) the period of this motion (b) the frequency of the motion (c) the amplitude of the motion (d) the first time after t=0 that the object reaches ...

**math**

a mystery number is bigger than 50 and larger than 100. you can make exactly five different rectangles with the mystery number of tiles. its prime factorization consists of only one prime number. what is the number

**math**

a mystery number is bigger than 50 and larger than 100. you can make exactly five different rectangles with the mystery number of tiles. its prime factorization consists of only one prime number. what is the number

**Physics**

The boom of a crane is 20 m long and is inclined 20ᵒ from the horizontal. A bucket of cement with a mass of 3000 kg is suspended from the upper end of the boom. What is the torque acting on the point where the boom is attached to the crane? A. 5.5 x 105 Nm. B. 3.5 x 105 ...

**psychometric test**

Hi i have been given an experiment paper on personality, in this we have to come up with an updated version of Eysencks (EPI) questionnaire. This is to measure extroversion only ,we are measuring concurrent validity. Im having difficult in answering the co varibles which is my...

**Algebra**

help me solve this equation by substitution. y^2− 4x^2 = 7 9y^2+16x^2 = 323

**chemistry**

ryeng i suppose? this is a very easy question 392.4*10-10= x cm xcm^3= ycm^3 ycm^3* 21.09= mass in grams since face centered unit cell has 4 atoms mass/4, then use the product of that to divide by 1.66*10^-24 = amu your result should be 191.84 amu

**Chemistry**

How do I change 3,3,4,4,5,5-hexamethyl-1-hexyne into it's molecular formula

**physics**

the coefficients of static and kinetic friction for stone on wood are, respectively, 0.5 and 0.4. if a 150 kg stone statue is pushed with just enough force to start moving across a wooden floor and the same force continues to act afterward. find the statue’s acceleration.

**Calc 2**

Use Taylor’s Estimate to bound the error of the n-th order Maclaurin approximation of sin(a), where a 2 [��; ].

**home economics**

a firm produces 20 units of output at a market price of #5, a marginal cost of $5, and an average cost of $3. what is the firms economic profit and is the firm maiximizing its economic profit. Is the formula market price-average cost x quantity 20?

**physics**

For a glass lens submerged in water (n=1.33), the critical angle of incidence at which total internal reflection begins to happen is 60.1 degrees. What is the index of refraction of the glass?

**physics**

A thin uniform rod (length = 1.4 m, mass = 2.5 kg) is pivoted about a horizontal, frictionless pin through one end of the rod. (The moment of inertia of the rod about this axis is 1/3 ML2.) The rod is released when it makes an angle of 45° with the horizontal. What is the ...

**physics**

A 67.5 kg hoop rolls along a horizontal floor so that its center of mass has a speed of 0.090 m/s. How much work must be done to stop it?

**physics**

What force must be applied to push a carton weighing 350 N up a 19° incline, if the coefficient of kinetic friction is 0.45? Assume the force is applied parallel to the incline and the velocity is constant. (Enter the magnitude of the force.)

**physics**

What force must be applied to push a carton weighing 350 N up a 19° incline, if the coefficient of kinetic friction is 0.45? Assume the force is applied parallel to the incline and the velocity is constant. (Enter the magnitude of the force.)

**physics**

What force must be applied to push a carton weighing 350 N up a 19° incline, if the coefficient of kinetic friction is 0.45? Assume the force is applied parallel to the incline and the velocity is constant. (Enter the magnitude of the force.)

**Physics- Elena please help!!!!**

A centrifuge in a medical laboratory rotates at an angular speed of 3500 rev/ min. When switched off, it rotates through 41.0 revolutions before coming to rest. (a) Find the angular speed in rad/s. (b) Find the displacement in radians. (c) Find the constant angular ...

**physics**

What force must be applied to push a carton weighing 350 N up a 19° incline, if the coefficient of kinetic friction is 0.45? Assume the force is applied parallel to the incline and the velocity is constant. (Enter the magnitude of the force.)

**Math**

If 7x + 5 = -2, find the value of 8x.

**Math**

If 7x + 5 = -2, find the value of 8x.

**eco365**

You should be ashamed of yourselve

**Algebra 1**

Say x is the number of boxes sold in week 1, then: Boxes in week 1: x Boxes in week 2: x + 5 Boxes in week 3: 2x + 10 Total boxes = 4x + 15 4x + 15 = 431 x = 104 So in week 1 there was sold x = 104 in week 2: x + 5 = 109 in week 3: 2x + 10 = 218

**Algebra 1**

integer 1 = a integer 2 = b b-a = 1 (b is one more than a) b-7 = 2*a (b is seven more than two times a) a = b-1 b-7 = 2*(b-1) b-7 = 2b-2 b = -5 so a should be -6 answer is C)

**Physics**

Beeef

**Physical Science**

630J

**Chemistry**

Dear sir, madam, I am having a little problem with the solution my chemistry book gives on the following problem: We have a person whose body vitamine C concentration decays according to the following formula: 1500*0,974^t. Question A is no problem, but then question B: "...

**Math**

angle ABC ~= angle ACB BD perpendicular AC The sum fo the three angles in any triangle is 180 degree. Prove: mangle CBD = 1/2 mangle BAC

**Math**

ÚABC ~= ÚACB BD perpendicular AC The sum fo the three angles in any triangle is 180 degree. Prove: mÚCBD = 1/2 mÚBAC

**PHY 101**

A 0.425-kg blue bead slides on a frictionless, curved wire, starting from rest at point where h = 1.50 m. At point , the blue bead collides elastically with a 0.675-kg green bead at rest. Find the maximum height the green bead rises as it moves up the wire. PLEASE HELP I HAVE...

**science**

What happens when you burn magnesium metal using the big idea of energy?

**math**

If μ = 500 and σ =10, z = -3.0 falls how many points below the mean?

**baking**

I don't have any choices that why i cant find it.

**baking**

when making french doughnuts the paste is piped into rings onto _____ _____ and is then lowered into the fat.

**Physics**

Vector , which is directed along an x axis, is to be added to vector , which has a magnitude of 5.0 m. The sum is a third vector that is directed along the y axis, with a magnitude that is 5.5 times that of . What is the magnitude of ?

**AP Physics**

A monkey is hanging from a branch located exactly 24 meters along the ground from the hunter. The monkey is 14 meters above the ground. The hunter aims directly at the monkey and fires a water balloon at the monkey just as the monkey releases his grip. The balloon has an ...

**physics**

A child operating a radio-controlled model car on a dock accidentally steers it off the edge. The car's displacement 0.58 s after leaving the dock has a magnitude of 7.1 m. What is the car's speed at the instant it drives off the edge of the dock?

**physics**

Stones are thrown horizontally with the same velocity from the tops of two different buildings. One stone lands twice as far from the base of the building from which it was thrown as does the other stone. Find the ratio of the height of the taller building to the height of the...

**Math**

1/2x+1/2=y

**physics**

A golf ball is dropped from rest from a height of 8.20 m. It hits the pavement, then bounces back up, rising just 5.40 m before falling back down again. A boy then catches the ball when it is 1.40 m above the pavement. Ignoring air resistance, calculate the total amount of ...

**Math**

Find the pattern and fill in the blank. 94 26 ___ 14 10

**Spanish**

Will you please check my grammar? Thanks! In a one-page, typed essay, describe what you would do if you were the governor of your state (or mayor of your city). Include what you would do regarding three separate issues of importance in your state (or town). Si yo fuera el ...

**Math/physics**

Known factors-weight 105 g---speed at start 60 mph---distance traveled 70 yds. Questions ,what is the rate of decelleration?, At what yard marker does it decellate to 35 mph For each 5 feet higher from start - how much farther does it travel. Thank you for your help, Tom

**physics**

the problem stated that the rod has expanded 1/4 its volume. I am looking for the heat supplied that has made its volume expand. please help :D

**physics**

How much heat is needed to be supplied to a 3.5 kg cylindrical rod if its volume changes by 1/4 of its original size? Assume that it is initially at 20K and that c = 2 cal/g.C and α = 8x10^2/C

**physics**

A 4.7 g bullet is fired horizontally into a 0.50 kg block of wood resting on a frictionless table. The block, which is attached to a horizontal spring, retains the bullet and moves forward, compressing the spring. The block-spring system goes into SHM with a frequency of 8.0 ...

**Physics**

What is the maximum theoretical efficiency of a steam engine operating between 60°C and 410°C?

**Calculus**

y=cos3x(sin^3)x

**Calculus**

derivative of y=tan^3(x)

**Calculus**

evaluate the limit: lim cos(x + pi/2)/x x->0

**Calculus**

Find the vector and scalar equations of the plane containing the line r=(3,5,1)+t(-2,3,1) and the point (1,2,3)

**Physics**

so 0.398/1.26 × 10^–6 m2=3.16x10^-7Pa

**Physics**

In a classroom demonstration, a 79.2-kg physics professor lies on a “bed of nails.” The bed consists of a large number of evenly spaced, relatively sharp nails mounted in a board so that the points extend vertically outward from the board. While the professor is ...

**chem**

If the density of copper is 8.92 g/ml what is the % error?

**math**

The exchange rate of U.S. dollars to British pound's is .63 you have $4000 to convert to British pounds. How many British pounds will you receive?

**MATH HELP**

A committee of 5 people is to be selected from student council. Council has 6 boys and 7 girls. What is the probability that the committee will have at least 3 boys? *** If you can show work that would be helpful (OPTIONAL)*** THANK YOU VERY MUCH!

**MATH**

A committee of 5 people is to be selected from student council. Council has 6 boys and 7 girls. What is the probability that the committee will have at least 3 boys? *** If you can show work that would be helpful (OPTIONAL)*** THANK YOU VERY MUCH!

**Physics(work and energy)**

but if i do that,then does it mean that i only supply 49000J to only overcome the work done agaist friction?

**Physics(work and energy)**

A cannon ball is fired so that it hits the wall at the top of a 10m tower.If the energy needed to destroy the wall is 49000 F and the mass of the cannon ball is 10 k, the minimum initial velocity of the cannon ball required to break the tower wall is A 100 m/s b 200 m/s c 300 ...

**physics**

A cat walks along a uniform plank that is 4 m long and has a mass of 7 kg. The plank is supported by two sawhorses, one 0.44 m from the left end of the board and the other 1.5 m from its right end. When the cat reaches the right end, the plank just begins to tip. What is the ...

**physics**

A trained dolphin leaps from the water with an initial speed of 12 m/s. It jumps directly towards a ball held by the trainer a horizontal distance of 5.50 m away and a vertical distance of 4.10 m above the water. In the absence of gravity the dolphin would move in a straight ...

**Business Finance**

Lisa Kane borrowed $8000 on an 8% 60 day note. After 15 days, Lisa paid $2000 on the note. On day 45, Lisa paid $1000 on the note. What is the total interest and ending balance due by the U.S. rule? Use ordinary interest.

**Chemistry**

The highest positive oxidation number that chlorine can exhibit an any compound is +7, whereas its most negative oxidation number is -1. Write the electron configuration of chlorine and explain why these are limiting oxidation numbers for chlorine.

**Algebra**

The body mass index I can be used to determine an individuals risk for heart disease. An index less than 25 indicates low risk. the formula for body mass index is I=700w/H^. W=weight and H=height, Jeromine is 67 inches tall. What weights will keep his body mass index between ...

**math**

3/8 = .375 3/8<1 1% = .01 3/8%= .00375 .00375*$800= $3

**math**

13000/20000=(1-0.04t) (13000/20000)-1=-0.04t [(13000/20000)-1]/-0.04=t t=8.75

**physics**

Thanks Elena

**physics**

An electron enters a region where there is a magnetic field with a strength of 0.5 T which points out of the page (electron has an initial speed of 150 m/sec and is moving to the left). Describe motion of charge in an magnetic field (In particular, what is the shape of the ...

**English**

What are the parts for the sentence "How many players are on a team?"

**Stats**

A manufacturer wants to increase the absorption capacity of a sponge. Based on past data, the average sponge could absorb 3.5 ounces. After the redesign, the absorption amounts of a sample of sponges were (in ounces): 4.1, 3.7, 3.3, 3.5, 3.8, 3.9, 3.6, 3.8, 4.0, and 3.9. What ...

**surface area and volume**

You is real Hannah

**Calculus 2 correction**

I just wanted to see if my answer if correct the integral is: ∫(7x^3 + 2x - 3) / (x^2 + 2) when I do a polynomial division I get: ∫ 7x ((-12x - 3)/(x^2 + 2)) dx so then I use u = x^2 + 2 du = 2x dx 1/2 du = x dx = ∫7x - 12/2∫du/u - 3/1∫1/u = (7x^2...

**Math**

A bag of 12 white marbles and 1/3 red marbles and 2/5 blue marbles what is the total marbles in the bag?

**Algebra 2**

Abelardo wants to create several different 7-character screen names. He wants to use arrangements of the first 3 letters of his first name(abe, followed by arrangements of 4 digits in 1984, the year of his birth. How many different screen names can he create in this way? A.72 ...

**Physics**

the wind blows with a force of 425N north on a sail boat, while the water exerts a force of 325N west on the sailboat. Find the magnitude and direction of the net external force on the sailboat.

**equation**

4x + 3(29-x) = 100 please show work

**Trig.**

0 greater or equal to t greater or equal to 1.6

**physics**

A 4.5 cm tall object is placed 20 cm in front of a spherical mirror. It is desired to produce a virtual image that is upright and 3.5 cm tall. (a) What type of mirror should be used? concave mirror convex mirror (b) Where is the image located? (Your answer should be positive ...

**science**

If the greatest potential energy is 100J will the kinetic energy of the object ever reach 100J?

**chemistry**

If you have 4.90 moles of Ba, how many liters of N2 would you have at STP?

**physics**

Two blocks, A and B (with mass 50 kg and 100 kg, respectively), are connected by a string, as shown in the figure below. The pulley is frictionless and of negligible mass. The coefficient of kinetic friction between block A and the incline is μk = 0.28. Determine the ...

**math - calculus**

The above answer is incorrect.. everything is right except v=9pi(h) differentiate both sides. gives you... dv/dt=9pi dh/dt 9/9pi= dh/dt. dh/dt= 1/pi

**chemistry**

The urine excreted by an adult patient over 24 hours was collected and diluted to give 2.000L sample. at ph 10 EDTA FORMS 1:1 COMPLEX WITH BOTH Mg2+ and Ca2+ and after buffering at this pH a 10mL aliquot of the sample required 26.81mL of 0.003474M EDTA for titration The ...

**math**

I think I got it....11 weeks

**math**

Thanks for your help but I still don't get it

**math**

john has a 25 gallon fish tank. John filled his fish tank today with 24 gallons of water. the water evaporates at a rate of 1.5 gallons per week week. John adds 2 gallons to the tank every other week. At which of the following times will the tank contain 17.5 gallons? a. ...

**Organic Chemistry**

How do you synthesize methysulfonyl benzene from Benzene?

**ALGERBRA**

Patricia owned so many posters that she decided to sell 63 of them to her friends. After selling the posters, she still had 172 left. Write and solve an equation to find the number of posters p Patricia had originally

**physics**

A mass m at the end of a spring vibrates with a frequency of 0.87 Hz. When an additional 602 g mass is added to m, the frequency is 0.59 Hz. What is the value of m?