# Posts by Charlie

Total # Posts: 484

**Physics**

A father pulls his son, whose mass is 26.7 kg and who is sitting on a swing with ropes of length 3.27 m, backward until the ropes make an angle of 35.6° with respect to the vertical. He then releases his son from rest. What is the speed of the son at the bottom of the ...

**Physics**

A 25.0-g metal cylinder is placed on a turntable, with its center 70 cm from the turntable's center. The coefficient of static friction between the cylinder and the turntable's surface is μs = 0.71. A thin, massless string of length 70 cm connects the center of ...

**Physics**

whats the answer?

**Physics**

what's the answer?

**Physics**

Calculate the dot product Ā·Ê(where Ê = Ē/E ~ is the unit vector in the direction of Ē ) and plot both Ā and Ê, showing how Ā·Ê is the projection of Ā on Ê. Ā= −4ˆi + 3ˆj Ē= 12...

**math**

what is the tenth term

**math packet**

11 nickles and 5 dimes

**math**

WOW! Thanks, I had trouble setting up the equation to solve. But it makes sense, like when solving an interest problem.

**math**

It is important for Bob to have a gross salary in his fifth year of at least $100,000. He is promised salary increases of 3 percent per year in the second and third years and 5 percent thereafter. What must be his starting salary be to achieve his goal? My original answer was...

**math**

Thank you.That one had me stumped, but the way you explained it makes sense. 0.4%

**math**

In order for a spacecraft to reach Earth's orbital velocity, it must achieve a speed of 17,500 mph in 610 seconds after its first stage burnout where it should have achieved a speed of 1530 mph. What percent increase in speed per second is necessary after first stage in ...

**math**

Got it. 8 quarters, 17 dimes, and 35 nickels. Thanks for the equations, that was what I had trouble setting up.

**math**

There are 60 coins in a box containing only nickels, dimes, and quarters. If there is one more than twice as many dimes as quarters, and the total value of all dimes is five cents less than the total value of all nickels, how many of each denomination are in the box?

**physics**

Damon's post is correct.

**science**

please help I need these too

**Chem**

The following questions refer to the following system: A total of 30.0 mL of a .10M solution of a monophonic acid (Ka = 1.0 x 10 ^-5) is titrated with .20M sodium hydroxide solution. 1) Before the titration begins, the pH of the solution is about A) 2 B) 5 C) 7 D) 9 E) 12 2) ...

**Algebra**

One month Ivanna rented 5 movies and 3 video games for a total of $29. The next month she rented 2 movies and 12 video games for a total of $71. Find the rental cost for each movie and each video game. Rental cost for each movie? Rental cost for each video?

**Algebra**

In a recent year, 16.3% of all registered doctors were female. If there were 47,600 female registered doctors that year, what was the total number of registered doctors? Round your answer to the nearest whole number.

**Dimensionless parameters**

Thanks alot Damon :)

**Dimensionless parameters**

The drag, D, on a sphere located in a pipe flow through which a fluid is flowing to be determined experimentally. Assume that drag is a function of the sphere diameter, d, the pipe dianeter, H, the fluid velocity, V, and the fluid density, p. a) What dimensionless parameters ...

**maths**

the lenght of a rectangle is 1cm more than its width,it has a area of 414cm2 what is the width to one decimal place?

**Calculus**

A trough is 15 ft long and 4 ft across the top, as shown in the figure. Its ends are isosceles triangles with height 3 ft. Water runs into the trough at the rate of 2.5 ft^3/min. How fast is the water level rising when it is 2 ft deep?

**Physics**

A hockey puck is hit on a frozen lake and starts moving with a speed of 12.2 m/s. Ex- actly 6.70 s later, its speed is 6.20 m/s. The acceleration of gravity is 9.81 m/s2 . a) What is its average acceleration? Answer in units of m/s2

**Algebra 2**

That persons name is spelled Karen and she's in my math class. I didn't post the question under that name.

**Math**

The total volume of the platform is 1250 cubic feet.

**Math**

A production crew is assembling a three-level platform inside a stadium for a performance. The platform has the dimensions of 4x long and 2x wide, the middle box has the dimensions of 6x long and 4x wide, and the bottom box has the dimensions of 8x long and 6x wide. What is ...

**Algebra 2**

oops wrong question.

**Algebra 2**

Thank you :-)

**Physics**

A 1000 kg car rounds a curve of radius 70 m banked at an angle of 12°. What is the magnitude of the friction force required for the car to travel at 82 km/h?

**Physics**

A 1.13 kg ball is connected by means of two ideal strings to a vertical, rotating rod. The strings are tied to the rod and are taut. The upper string is 24.0 cm long and has a tension of 31.5 N, and it makes an angle θ2 = 51.0° with the rod, while the lower string ...

**math**

how many four letter words can be made fro the letters p,a,y,m,e,n,t with no repetition of any letters?

**math**

a clock strikes only in the hour (once at 1.00,twice at 2.00 etc) how many times will it strike in one 24 hour day? please explain,thanks

**physics**

A 2.60 kg steel gas can holds 15.0 L of gasoline when full. What is the average density of the full gas can, taking into account the volume occupied by steel as well as by gasoline?

**math-statistics**

a and b are obove 1. The rest are between 1. answer A and B

**Geometry**

A. Derive the distance formula (d) shown below for points A = (x1, y1) and B = (x2, y2). 2 2 1 2 2 1 d = (x − x ) + ( y − y ) Note: Look for an application of the Pythagorean theorem where the red line, segment AB, is the hypotenuse of a right triangle. You can ...

**Literature**

How does Kurt Vonnegut address the concept of equality differently in “Harrison Bergeron” than Martin Luther King Jr. does in “Letter from Birmingham Jail”? What relationship does Vonnegut’s story show between equality and personal freedom/individual ...

**Math**

I am an even two digit number. I have the same digit in my ones place and my tens place. The sum of my digits is 8. The product of my digits is 16. What number am I?

**Chemistry**

Calculate Kp at 298K for the reaction SO2 + NO2--->SO3 + NO

**General Chemistry**

First, Determine the number of moles you have of C6H6 (16 g / molar mass (78)) = .206 Moles C6H6 Now its good ol stoichiometry Using the formula given 2 moles of C6H6 produce the -6536 kJ .206 C6H6 * -6536kJ / 2 moles C6H6 = -673.208 (or so)

**Trig**

A 12 foot ladder leans against a building. The top of the ladder leans against the wall 10.5 feet from the ground. What is the angle formed by the ground and the ladder? Assume its a right triangle.

**Geometry**

Mike and Lani stand 21.2 meters apart. From Mike’s position, the angle of elevation to the top of the Eiffel Tower is 40°. From Lani’s position, the angle of elevation to the top of the Eiffel Tower is 38.5°. How many meters high is the Eiffel Tower? Round to...

**rate constant**

A reaction has a rate constant of 1.25×10−4 at 28 and 0.227 at 77. Determine activation barrier for reaction What is the value of the rate constant at 18?

**Physics**

Calculate the amperage of the lights: watts/volts= Amps. Then divide the battery's capacity by the answer.

**Binomial Math**

Nice answer you idiot.

**Physics**

The crate, m=68kg, is pushed up an incline, θ=24degrees, at a constant velocity with Fp=500N. μk=?

**algebra**

i have 8 yards of fabric. how many yards of fabric will i have left over if i made 3 small costumes with 2 5/8 yards

**math**

there are 4 students sitting to receive their prizes. Alan and Julia wanted to sit together. how many different arrangements of students would there be

**math**

what is the square root of 6,multiplies the answer bt 2 and then squares that answer.please explain,thanks

**math**

a box contains more than 25 but less than 40 balls.when we counted by 3 there are 1 left over,when we counted by 5 there are 2 left over.how many balls are there in the box ? please explain how you work it out,thanks

**math**

find the number of fifths in one and four fifths

**math**

Iused 8 cubes to make a large cube.How many cubes will i need to make a 4^4^4 cube ?

**Chemistry**

An unknown solution may contain one of the ions of the pair below. Devise a test which allows you to distinguish between the ions. Cu2+(aq) and Co2+ (aq)

**math**

how many twelths in 3.1/2 ?

**math**

what is the next number in the sequence 2,3,7,16,32,______ .

**math**

4C =2A + 2B , 2B = A + 3C How many C's will balance the combination of A and B

**math**

the average mark of 10 tests is 76%.If the average mark of the first 7 tests was 73%,what is the average mark of the remaining 3 test

**math**

at rush hour,240 people pass through a turnstile at a railway station each 5 minutes.If there are 8 turnstiles, how many people would pass through them all in an hour

**math**

From hundreds chart;How to work out what % of the numbers are multiples of 3?

**math**

there are 3 different ways of travelling from A to B and 5 different ways of travelling from B to C. How many different ways are there of travelling from A to C through B ?

**math**

what number is 100 times less than 600

**math**

A 3 cm cube is painted on all its faces.It is then cut into 1 cm cubes. How many cubes will have paint on exactly 2 faces ?

**math**

there are 3 different ways of travelling from A to B and 5 different ways of travelling from B to C. How many different ways are there of travelling from A to C through B ?

**math**

we had to go 30km through the city and then 30km through the country.Through the city we averaged 40km/h and through the country we averaged 60km/h.What was our average speed for the entire journey ?

**math**

A bus stopped at Gulgong, 25% of the passengers got off the bus and 3 new passengers got on. At the next stop,3 quarter of the passengers got off the bus and 11 new passengers got on. The bus then had 17 passengers.How many passengers did the bus have just before it stopped at...

**math**

An open steel tank measures 2m by 2.5m by 3m.It holds 7500 ml of water. What is the volume of steel,in cubic metres,making up the sides of the tank ?

**math**

a tank is made in the shape of a rectangular prism, measuring 12 cm by 16 cm by 10 cm.It is full of water.A small rectangular prism measuring 2 cm by 3 cm by 4 cm is dropped into the full tank. What is the amout of water which overflows?

**math**

use the hundreds chart to answer this question; what percent of the numbers are multiples of 3 ?

**physics**

a jet plane traveling at +87 m/s lands on a runway and comes to ret in 11 s. a)Calculate its uniform acceleration b)Calculate the distance it travels

**physics**

top-fuel drag racers are able to uniformly accelerate at 12.9 m/s from rest 97 m/s before crossing the finish line . How much time elapses during the run ?

**Calculus**

lim (2Q^(2)+5)/(q+2) q->2 lim |y+3| y->-3

**Maths**

For y= 2x squared + x - 1 the x-intercepts and the turning point respectively are?

**physics**

The two angled ropes used to support the crate in Figure P5.7 can withstand a maximum tension of 1500 N before they break. What is the largest mass the ropes can support?

**Chemistry**

In a titration of 35.00 mL of 0.737 M S, __________ mL of a 0.827 M KOH solution is required for neutralization.

**Chemistry**

In a titration of 35.00 mL of 0.737 M S, __________ mL of a 0.827 M KOH solution is required for neutralization.

**Physics**

21

**chemistry**

how would you, explain ans how calcium chloride [CaCl2] is bonded.

**physics**

Initial velocity, (u), is given, so is acceleration, (g), so is the distance (s), 28.4m. Use v^2=u^2+2as and solve for v.

**earth science**

descibe the advanages of plotting data in graph form

**Physics**

Eric, I'm not sure what you need, but if it's Physics tuition (or Math)try Khan Academy. Hundreds of short vids. Hope Jiskha don't mind this post.

**5th grade math**

The moon is about 240.000 miles from earth. What is this distance written as a whole number multiplied by a power of ten

**Physics**

Force = Massx acceleration. Find the accel using v=u+at, solving for a. v is the final velocity (0); u is the initial (9.4), t is time (0.2) Then x by 110 kg. to get the force in Newtons.

**Geometry**

B is between A and C. Solve for x, if AB=2x+6, BC=4x-3, and AC=5x+12

**AP Physics**

V^2=u^2+2as. v= the final velocity; u=the initial velocity (9.2 m/s; a is accel and s is distance (more accutately, displacement). Solve for v.

**AP Physics**

The ball goes 120m in time t. t, or fall time, is sqrt of 2h/g, both given. 120/t gives the x component of velocity in m/s.

**Physics**

Picture a right angled triangle with one side AB being 25 x 125 metres long to the west; the other side BC being 19 x 66 metres long to the south. The displacement is the length of the hypotenuse AC; the direction being between 180 degrees and west. Sketch it out, then do the ...

**Physics**

Assuming the 'passing the window'part means 0.10s to go from the top to the bottom of the window... Then the veocity will be 1.18/0.1, so 11.8m/s. Accel will be that of 'g', so 9.8 m/s^2; and the initial velocity was 0 m/s. Use v^2=u^2+2as Solve for s, which ...

**physics**

Initial velocity is given, final velocity is given, and the time is given. Using these, rearrange v=u+at to solve for a. The ball is slower after the bounce, so what sign will the acceleration be?

**physics**

a) use v=u +at solve for a b) use v^2=u^2+2as solve for s. v is final vel; u is initial vel; t is time and a is accel. S is displacement; or distance in this case.

**PHYSICS**

Hor vel= 300cos55 Mult this by 42s to get the horizontal (x) distance. (42s btw is a bit ridiculous, but hey ho)

**Physics**

c=f*lambda, or the speed of light =the frequency x the wavelength. Solve for wavelength, and remember to divide by 4 for a quarter.

**algebra**

Multiply EVERY term in the second bracket by -x; then do the same with the -1. Gather all the like terms together: all the exponents, then all the x terms and then all the numbers.

**Math**

what is the value of 200 dimes? Subtract the answer from $28.10. How many quarters in your answer?

**physics**

The ball's horizontal and vertical components are independent of each other. The 11m per sec makes no difference to your calculation. You know the starting vertical vel( 0m per sec); the time,(4.8sec) and the acceletation (g). Use v=u+at to get the velocity at 4.8 sec, ...

**Physics**

Drwls Could it also be solved by using v=u+at for the upward throw;then another motion equation for the upward distance; added to the fall time (sqrt 2h/g) all the way to the bottom? Charlie

**Math**

I'm on the same problem and I'm having trouble solving it, can you go into a bit more detail.

**Physics**

Assuming air resistance is negligible.

**physics**

What do you know? Initial velocity 5 m/s Time 6s Displacement (distance, not quite the same)60m Look at the standard motion equations, see if you can find one that uses all of these to give acceleration. Then use v=u+at.

**physics**

Hint: what speed was the coin doing along the ground before you threw it?

**physics**

Weight is Mass (m) x acceleration due to gravity (g). W=mg So,to get back to mass, divde the weight by g. 84.5/9.81= ?kg Now adjust the value for g for when the elevator is going up or down (add or subtract the elevator velocity)and multiply it by the mass you calculated. When...

**math**

How can I calculate how long an amount of money will last if I spend x dollars per month, at the same time as the pot of money is attracting interest at y percent? Is thare a formula? Thanks