# Posts by Phil

Total # Posts: 298

**Physics**

Force equals mass times acceleration...the mass of your vehicle is the same, always. The acceleration is also to be considered the same for both problems. So if both equations, (one for collision with wall, and one for other car) have the same numbers, then the forces are ...

**Physics**

hah I love how everyone in physics with Kaminsky is looking here

**Algebra**

What is the inverse of y = (3/7)x + 9 I know you have to switch x and y so I get to x-9=(3/7)y from there I don't know what to do.

**Physics- PLEASE HELP**

Two boxes of fruit on a frictionless horizontal surface are connected by a light string as in the figures below, where m1 = 15 kg and m2 = 17 kg. A force of 58 N is applied to the 17 kg box. Repeat the problem for the case where the coefficient of kinetic friction between each...

**Physics- PLEASE HELP**

Two boxes of fruit on a frictionless horizontal surface are connected by a light string as in the figures below, where m1 = 15 kg and m2 = 17 kg. A force of 58 N is applied to the 17 kg box. Repeat the problem for the case where the coefficient of kinetic friction between each...

**physics**

A bicycle wheel of radius 0.4 m is spinning at a rate of 40 revolutions per minute. What is the centripetal acceleration of a point on the edge of the wheel? What is the period of the wheel's motion?

**Math**

The way this is written you need to A:conduct three trials using three different coins (1 for each trial). For each trial flip the coin three times & record the results (heads even & tails odd). Each flip represents one of the three misses for that route. B: Actually do the ...

**statistics**

thanks!

**statistics**

So if a scale has 30 items in it, and if an individual gets a score of 20 what does this mean? The only way to answer this is to look at the standardization sample, find out what the mean score in the sample was, let's say 15, and standard deviation in the population was ...

**statistics**

So if a depression scale has 30 items in it, and if an individual gets a score of 20 what does this mean? The only way to answer this is to look at the standardization sample, find out what the mean score in the sample was, let's say 15, and standard deviation in the ...

**Physics**

HELP WITH c.!!! A electric bill showed 1200 kilowatt hours (kWh) purchased at a cost of $150.00. a. What does PECO charge per kWh? $0.125 b. An electric dryer is rated at 5400 W. It takes 40 minutes to dry a normal load. What is the cost per load? $0.45 c. Two 100 watt ...

**physics**

Microwaves are electromagnetic waves transmitted at a normal frequency of 2.45 GHz. Find the wavelength of the microwaves.

**SCIENCE**

WHAT IS THE FUNCTION OF GUARD CELLS?

**PHYSICS**

A BODY CHANGES IT'S VELOCITY FROM 20M/S UNTIL IT COMES TO REST IN 10 SECONDS.WHAT IS IT'S ACCELERATION

**PHYSICS**

A LORRY INCREASES VELOCITY FROM 6m/s TO 10m/s IN 25 SECOND.FIND THE ACCELERATION.

**Physics 121**

Two block are connected by a rope that runs over a pulley. The block on the tables has mass 4kg, the hanging block has mass 2kg, and the pulley has mass 0.5kg and radius 0.25m. Assume that the table is friction-less. If the block are released from the rest, determine their ...

**Math**

1. P = positive results / total attempts. In this case, 11/50 = .22 = 22% 2. Increase the sample size. The more data he accrues, the closer the experimental probability will be to the theoretical probability.

**Chemistry**

1. You are correct. The strength of a weak acid is proportional to its dissociation constant, which is directly proportional to the concentration of ions and inversely proportional to the concentration of the undissociated acid molecules. 2. Yes, this is correct. The pH ...

**physics help please**

My answers would be a, b, and d, where b and d are the same force. This assumes you are traveling very fast.

**College chemistry**

This is an example of a combustion reaction involving a hydrocarbon (in this case propane) reacting with oxygen. The products of such reactions are almost always water and carbon dioxide. C3H8(g) + O2(g) → H2O + CO2 First balance the number of Carbons on both sides. ...

**chemistry**

You are actually really close. First remember that ΔG = Greactants - Gproducts. In this case the equation is: Ba2+ + NO3- -> Ba(NO3)2 But that equation isn't balanced! For this to work you have to balance the equation first like so: Ba2+ + _2_NO3- -> Ba(NO3)2 ...

**physics**

A +50 micro coulomb and 30 micro coulomb charge are placed 50cm apart. a)what is the direction and magnitude of thee electric field at a point P, in between them, that is 10cm from the 30 micro coulomb charge? b)if an electron is placed at rest P, what will its acceleration be...

**physics**

A +50 micro coulomb and 30 micro coulomb charge are placed 50cm apart. a)what is the direction and magnitude of thee electric field at a point P, in between them, that is 10cm from the 30 micro coulomb charge? b)if an electron is placed at rest P, what will its acceleration be...

**MATH**

if I scored 72 out of a 100, what do i need to score to bring up may average to 80%

**Physics**

HELP! A tennis ball is attached to a .8m long string whirled around in a circle with a constant frequency of 1.2 Hz. What is the linear(tangential) velocity of the tennis ball?

**physics**

A wooden box weighing 271 N is pushed across the floor by a workman who exerts a horizontal force of 144 N. If the force of friction between the box and the floor is 28 N, what is the acceleration (in meters/second^2) of the box?

**Probability**

how many can 5 people be arranged in a row if the father is on the far right?

**Physics**

A vibration platform oscillates up and down with an amplitude of 10.2 cm at a controlled variable frequency. Suppose a small rock of unknown mass is placed on the platform. At what frequency will the rock just begin to leave the surface so that it starts to clatter?

**Physics**

Two electrons are fixed 2.99 cm apart. Another electron is shot from infinity and stops midway between the two. What is its initial speed?

**Physics**

you screwed buddy

**physics**

Kole is right but how would you find velocity

**Physics**

This question contains a graph: h t t p : / / i . i m g u r . c o m / Q z l x d . p n g

**Chemistry**

Calculate the heat released from 61.5 g of steam at 111 degrees C is converted to water at 39 degrees C. Assume the specific heat of water is 4.184 J/g*C, the specific heat of steam is 1.99 J/g*C and the enthalpy.H.vap= 40.79 KJ/mol of water

**Chemistry**

What is the Heat Change in kilojoules when 61.5 g of steam is cooled from 111 degrees C to 100 degrees C?

**Physics**

Figure (a) shows charged particles 1 and 2 that are fixed in place on an x axis. Particle 1 has a charge with a magnitude of |q1| = 12.0e. Particle 3 of charge q3 = +13.0e is initially on the x axis near particle 2. Then particle 3 is gradually moved in the positive direction ...

**Physics**

Figure (a) shows charged particles 1 and 2 that are fixed in place on an x axis. Particle 1 has a charge with a magnitude of |q1| = 12.0e. Particle 3 of charge q3 = +13.0e is initially on the x axis near particle 2. Then particle 3 is gradually moved in the positive direction ...

**Math**

What's the least common multiple of 2 and 2.5?

**Physics**

This problem contains a graph: h t t p : / / i . i m g u r . c o m / p s z e p . p n g

**Physics**

Here is the problem in image form: h t t p : / / i . i m g u r . c o m / g n 1 j R . p n g

**Physics**

Sphere W (with an initial charge of zero) is touched to sphere A and then they are separated. Next, sphere W is touched to sphere B (with an initial charge of -26e) and then they are separated. Finally, sphere W is touched to sphere C (with an initial charge of 46e), and then ...

**Physics**

They're all the same size.

**Physics**

Sphere W (with an initial charge of zero) is touched to sphere A and then they are separated. Next, sphere W is touched to sphere B (with an initial charge of -26e) and then they are separated. Finally, sphere W is touched to sphere C (with an initial charge of 46e), and then ...

**homework**

every yellow marble is expensive.one -half the orange marbles are expensive.one -half of all expensive marbles are yellow. there are 40 yellow marbles and 25 expensive marbles that are niether yellow nor orange. how many orange marbles are there?

**Statistics**

Suppose you know ó and you want an 85 percent confidence level. What value would you use to multiply the standard error of the mean by?

**Electric Fields**

In a particular region of Earth's atmosphere, the electric field above Earth's surface has been measured to be 151 N/C downward at an altitude of 280 m and 167 N/C downward at an altitude of 430 m. Calculate the volume charge density of the atmosphere, assuming it to ...

**Physics**

A chair with a mass of 30.0kg is shot with a 10g bullet traveling at a speed of 250m/s. The bullet goes 6cm into the chair. The given kinetic friction for for this problem is .2. How far does the chair slide in cm?

**Physics**

The coefficient of kinetic friction for a 22 kg bobsled on a track is 0.15. What force is required to push it down a 6.0° incline and achieve a speed of 64 km/h at the end of 75 m?

**Physics**

A person throws a ball upward into the air with an initial velocity of 15.0 m/s. Calculate the following: a.) how high it goes. b.) how long the ball is in the air before it comes back to his hand. c.) at what time(s) will the ball pass a point 8.00 m. If you got multiples ...

**Physics**

Units count. Show all steps, not just the numerical substitutions. Show the equations you used. No information is missing. A person throws a ball upward into the air with an initial velocity of 15.0 m/s. Calculate the following: a.) how high it goes. b.) how long the ball is ...

**Modern Physics**

(7) Show that if a particle moves at an angle θ with respect to the x-axis with speed u in frame S, then it moves at an angle θ′ with the x′-axis in frame S′ with tanθ′ = sinθ /( γ(cos θ − v/u)) Assume that S′ ...

**University Physics**

If vector B is added to vector C = 6.7 + 6.9, the result is a vector in the positive direction of the y axis, with a magnitude equal to that of vector C. What is the magnitude of vector B?

**University Physics**

If is added to = 6.7 + 6.9, the result is a vector in the positive direction of the y axis, with a magnitude equal to that of . What is the magnitude of ?

**physics**

Determine the stopping distances for a car with an initial speed of 93 km/h and human reaction time of 3.0 s for the following accelerations: -4.00 m/s^2 -8.00 m/s^2

**physics (non-calc)**

A particle of charge 2.5x10(^-6)C is moving at 1000 m/sec in a direction 30 degrees North of east. At the location of the particle the magnetic field has size 0.2 T. The particle is experiencing an instantaneous magnetic force (due to this sheild) of 1.71x10(^-4) newtons ...

**game theory**

Two companies, A and B, produce widgets. Each can produce 0, 1, 2, 3, or 4 widgets (they canâ€™t produce fractions of widgets). Let X be the number of units produced by A, and Y be the number of units produced by B. Given X and Y, widgets will sell at a price ...

**economics**

Two companies, A and B, produce widgets. Each can produce 0, 1, 2, 3, or 4 widgets (they canâ€™t produce fractions of widgets). Let X be the number of units produced by A, and Y be the number of units produced by B. Given X and Y, widgets will sell at a ...

**Chemistry**

Trista is almost correct. However she failed to realize that the problem called for 100 mg which is equal to 0.1 grams. This means that (7.05x10^-3)g/L / 0.1g = 0.0705/1L (Where the L is in the denominator). So in order to finalize this problem all you have to do is take the ...

**Math**

How many ml are there in .032L ?

**Physics**

Can someone please help me? The brakes of a truck cause it to slow down by applying a retarding force of 2.60 103 N to the truck over a distance of 930 m. What is the magnitude of the work done by this force on the truck? Is the work positive or negative? Explain Why?

**Calculus**

Find the equation of the plane through (1,2,-2) that contains the line x = 2t, y = 3 - t, z = 1 +3t

**Calculus 3**

Show that if a, b, c are in V3, then (a x b) dot [(bxc)x(cxa]) = [a dot (b x c)]^2 I don't know what properties to use

**Vectors**

Show that if a, b, c are in V3, then (a x b) dot [(bxc)x(cxa]) = [a dot (b x c)]^2 I don't know what properties to use

**physics**

The answer is 200N in the sense that an increase in force will produce an increase in the acceleration.

**Physics**

Nevermind. The answer is 250 degrees Celsius. Duh!

**Physics**

(brass diameter)*(1+(brass coefficient)*(change in brass temperature)) = (iron diameter)*(1+(iron coefficient)*(change in iron temperature)) where: brass coefficient = 19*10^-6 K^-1 iron coefficient = 12*10^-6 K^-1

**Physics**

A brass plug is to be placed in a ring made of iron. At 20 degrees Celsius, the diameter of the plug is 8.737 cm and that of the inside of the ring is 8.723 cm. They must both be brought to what common temperature in order to fit? (ANSWER: -210 degrees Celsius) What if the ...

**Algerbra**

f(x)=4x^2+7x-5 and g(x)=-9x^2+3x-14

**Physics - Buoyancy**

A scale reads 20.3 N when an object is not submerged in water and 20.0 N when the object is (completely) submerged in water. What is the specific gravity of the object?

**Chemstry**

This implies that the double and triple bond are adjacent to eachother, so that would give the N an expanded octet of 10 electrons, but I thought that only happened after P?

**Chemstry**

What is the structure of N4O, where the 3 nitrogen bonds have different bond lengths and the N=O bond is a double bond. I just don't get it

**chemistry**

Am I right with my answer?

**chemistry**

A tragedy hits a small town. The elementary school explodes into flames trapping several classes of second graders. Because the volunteer fire department will take too long to get there, teachers and classified staff remove all the children to safety without considering the ...

**science**

If it happens that a neurotransmitter binds to a receptor site and produces a negative voltage shift, the probability: that the neurons are densely connected decreases. of an excitatory response increases. that the receiving neuron will fire decreases. that the transmitting ...

**general**

Neurons receive communication through dendrites which act as antennae. Transmitting these initial messages to other neurons is the function of the: cell body. synapse. cerebellum. axon. Im between A and D. Please help.

**Physics**

A 13 cm long animal tendon was found to stretch 3.8 mm by a force of 13 N. The tendon was approximately round with an average diameter of 9.0 mm. Calculate the elastic modulus of this tendon.

**social studies**

how much respect is given to older people

**Physics**

Estimate the work you do to mow a lawn 14m by 23m with a 0.5m-wide mower. Assume you push with a force of about 15N.

**Physics**

Estimate the work you do to mow a lawn 14m by 23m with a 0.5m-wide mower. Assume you push with a force of about 15N.

**Physics**

h t t p : / / b i t . l y / 9 S F F F o a) What is the minimum value of F needed to move the two blocks? b) If the force is 10% greater than your answer for (a), what is the acceleration of each block?

**Physics**

Three Coulombs of charge flow through a wire in 150 ms. If the current ceases to flow (goes to zero Amps) for the following 850 ms, what is the average current over this one-second period?

**Physics**

A 48V battery delivers power to a golf cart. The golf cart drives for 45 seconds while the batteries deliver 12A of current. How much energy (in Joules) is delivered during the drive?

**Physics**

A 1100 kg car is moving toward the north along a straight road at a speed of 20.0 m/s. The driver applies the brakes and the car comes to rest in a distance of 140 m. (a) If the road is completely level, what is the constant force applied to the car to bring it to rest? (...

**Physics**

A 1100 kg car is moving toward the north along a straight road at a speed of 20.0 m/s. The driver applies the brakes and the car comes to rest in a distance of 140 m. (a) If the road is completely level, what is the constant force applied to the car to bring it to rest? (...

**Physics**

A sprinter starts from rest in a 100-meter race, accelerates to his full running speed of 10.3 m/s in 1.15 seconds (assume constant acceleration) and continues at that speed for the rest of the race. (a) How far did he run before attaining his full speed? (b) What was his ...

**Physics**

{ The subscripts are in curly brackets } A mass m is at rest on a horizontal frictionless surface at t=0. Then a constant force F{0} acts on it for a time t{0}. Suddenly, the force doubles to 2F{0} and remains constant until t=2t{0}. Determine the total distance D traveled ...

**Physics**

A child on a sled reaches the bottom of a hill with a velocity of 12.0 m/s and travels 22.0 m along a horizontal straightaway to a stop. If the child and sled together have a mass of 59.0 kg, what is the magnitude of the average retarding force on the sled on the horizontal ...

**Physics**

Estimate the average force exerted by a shot-putter on a 6.5 kg shot if the shot is moved through a distance of 2.7 m and is released with a speed of 11 m/s.

**Physics**

1.) Describe the proper way to use a meter stick and why this technique is necessary (include an explanation of uncertainty). 2.) What is the difference between percent error and standard error?

**chem - br bob is this right**

What is the pH of a solution prepared by adding 4.000 grams of NaOH to a 50.00 mL of a buffer that is 2.00 molar both in acetic acid and sodium acetate? (Assume final volume is still 50.00 mL) * chem - DrBob222, Wednesday, April 21, 2010 at 10:52pm * chem - phil, Wednesday, ...

**chem**

i did .1 mols of AC- + .1 mols of OH gives me .2 mols of AC. the .2 mols of AC reacts with water AC- + H20---> OH- + HAC so the M is .2/.05 L = 4M to solve for the OH conc i did X^2 / 4 = 5.6 x 10^-10. and solving for the pH i get 9.675 is this right?

**chem**

What is the pH of a solution prepared by adding 4.000 grams of NaOH to a 50.00 mL of a buffer that is 2.00 molar both in acetic acid and sodium acetate? (Assume final volume is still 50.00 mL)

**chem**

I don't think this would be correct because The solution you are proposing would have a pH over 12.

**chem**

how many mL of .100 M of acetic acid and .100 M of NaOH, would be need to make the volume 1.0 liters and have a pH7.00 if Ka=1.8x10^-5 please write out the steps or eq for me im gettin stuck

**Biology**

37 is a and 38 is i think a and b

**Math**

Yes "A" has reflective symmetry, not rotational symmetry.

**physics**

The mass times the coefficient of friction

**math**

Two angles are complementary. THe sum of the measure of the first angle and one forth of the second angle is 58.5 dagrees. Find the measure of the angles.

**math**

20% of num is x. the num is 4 more than x . what's the number.

**chemistry**

How many Ca +2 ions in 40.08g of CaCO3 (Calcium Carbonate) I'm unsure on how to approach this problem and set it up.

**accounting**

Your rich godfather has offered you a choice of one of the three following alternatives: $10,000 now; $2,000 a year for eight years; or $24,000 at the end of eight years. Assuming you could earn 11 percent annually, which alternative should you choose? If you could earn 12 ...