jaimie r

1. The volume of a gas is 25mol when the pressure is 1atm. at the same temperature, what is the pressure at which the volume is 18ml?

2. The volume of a gas in 10L when the temperature is 7C. if the temperature is increased to 12C without changing the pressure, what is the new volume (convert temperature to kelvin) Thank you for your help. I am unsure which equation I should use.

So I am helping my little cousin with Chemistry and he has NO materials/books/examples. The question asks A mixture of 4 gases exerts a total pressure of 920 torr. Gas A has a partial pressure of 530 torr, gas B has a partial pressure of 75 torr and gas C has a partial pressure of 105 torr. What is the partial pressure of gas D. I know the rule is Ptotal= Pa+ Pb+Pc+Pd... so it should be 920-530-75-105 correct? Should the solution be this simple or am I missing something?

I need help with this question: follow link below please!

http://answers.yahoo.com/question/index;_ylt=AgblG...

Thanks in advance :)

Using Kirchhoff's rules, calculate the current in R1 with the directions indicated in the figure below.

IMAGE: https://spock.physast.uga.edu/res/brookscole/serwa...

Assume that R1 = 4.00 kohm, R2 = 6.00 kohm, R3 = 8.00 kohm, E1 = 75.0 V, E2 = 60.0 V and E3= 85.0 V.

Calculate the current in R 1, R2 and R3...

Find the magnitude of the potential difference between points c and f.

What is the emf, E, of the battery in the circuit of the figure below?

Figure: https://spock.physast.uga.edu/res/brookscole/serwa...

Assume that R1 = 1.10 ohm, R2 = 3.10 ohm, R3 = 5.00 ohm, R4 = 1.40 ohm, R5 = 11.0 ohm, V = 6.00 V and I = 1.80 A.

I don't know why I am having soo much trouble with this. I have combined resistors 1 and 2 in series and 3 and 4 in series and applied the loop rule and I am still getting an incorrect answer... any suggestions?

A charge of 24.6 microC is located at (4.49m, 6.08m) and a charge of -11.2 microC is located at (-4.43m, 6.74m). What charge must be located at (2.28m, -2.94m) if the electric potential is to be zero at the origin?

I know that it is a scalar quantity and that we should add v1 v2 and v3 but I am not sure how to visualize the problem or set it up correctly. I believe that I am having issues with my signs... Thanks for your help!

A) An electron has an initial speed of 4.50×106 m/s. What potential difference (sign and magnitude) is required to bring the electron to rest?

-57.6 V (this is correct)

B) what potential difference is required to reduce the Kinetic energy of the electron be a factor of 5 compared with the initial value?

*** I multiplied my answer for A by 1/5 and it is incorrect

C) What potential difference is required to reduce the speed of the electron be a factor of 5 compared to the initial speed?

*** I tried multiplying my answer for A by 1/25th and this is incorrect ...

PLEASE HELP :(

Two point charges lie on the x axis. A charge of +6.34 microC is at the origin, and a charge of -9.80 micro C is at x= 12.0 cm. What is the net electric field at x= -4.14 cm? And x=4.14cm

I have seen similar problems on yahoo answers and I have tried to follow those steps using my numbers and still cannot get the answer correct ... I keep getting 2.99e^7 n/c for -4.14 and that's wrong! Please help!!

A small block of mass m1 = 0.5 kg is released from rest at the top of a curved wedge of mass 7.0 kg, which sits on a frictionless horizontal surfac. When the block leaves the wedge, its velocity is measured to be 4.8 m/s to the right, as in Figure P6.59b. (a) What is the velocity of the wedge after the block reaches the horizontal surface?

I found the answer to A) and it is -0.343 m/s

PART B) ... what is the height of the wedge?

I cannot figure out part B... I tried using

mgh= 1/2 mv^2 and I got a height of 1.7 meters... this is incorrect and I am clueless :(

Thanks in advance for the help! :D

Two cars collide at an intersection, but do not "stick together" after the collision. Therefore, the collision was elastic.

It is possible for two isolated objects to collide so that all the initial kinetic energy of the system is lost.

A system of particles with zero kinetic energy must also have zero momentum.

An object at rest on a slick surface is struck by a second object. After the collision, both objects must be moving.

A system of particles with zero momentum must also have zero kinetic energy.

An appliance box has a square base with sides of length L, and has rectangular sides with a height of 4L. The top of the box is missing. The box is made from cardboard of uniform thickness and density. What is the height of the center of mass of this open box, with respect to the bottom of the box?

I am beyond lost on how to even set this up...any advice? I thought it would be 4* 4L^2 * 4L/2 to get 32L^3

and the total box would be 16L^2 so I go 2L and that is NOT right. Any suggestions?

32L/17

4L/5

8L/17

16L/17

2L

A 0.341 kg pendulum bob is attached to a string L = 1.12 m long. What is the change in the gravitational potential energy of the system as the bob swings from point A to point B? theta = 37.3°.

Ok so I have tried finding the height using H/L = sin(37.3) then plugging that height into

Pe= mgh

I also tried U=mg (delta)h or more simply mgL(1-cos 37.3) and I cannot seem to get the correct answers

I tried .678 and .7662 and neither are correct... should my answers be negative? I am soo confused. Thanks in advance for the help!!

Calculate the coefficient of kinetic friction between a 4.82 kg block and the horizontal surface on which it rests if an 82.3 N/m spring must be stretched by 2.21 cm to pull it with constant speed. Assume that the spring pulls in a direction 13.4° above the horizontal.

Calculate the coefficient of kinetic friction between a 4.82 kg block and the horizontal surface on which it rests if an 82.3 N/m spring must be stretched by 2.21 cm to pull it with constant speed. Assume that the spring pulls in a direction 13.4° above the horizontal.

I have tried this problem 3 different ways, assuming that the Fk=Fs and then adding in the force in they y direction as (1-sin(theta).... I am lost

A soccer ball is kicked with an initial speed of 10.3 m/s in a direction 25.7° above the horizontal.

1. Calculate the magnitude of its velocity 0.360 s after being kicked.

I got 9.33 m/s...this is correct

2. What was its direction?

I am not sure how to solve for direction

3. Calculate the magnitude of its velocity 0.720 s after being kicked.

9.64 m/s is correct

4. What was its angle relative to the horizontal (choose positive for above and negative for below)?

Not sure how to solve for this angle :(

A soccer ball is kicked with an initial speed of 10.3 m/s in a direction 25.7° above the horizontal.

1. Calculate the magnitude of its velocity 0.360 s after being kicked.

I got 9.33 m/s...this is correct

2. What was its direction?

I am not sure how to solve for direction

3. Calculate the magnitude of its velocity 0.720 s after being kicked.

9.64 m/s is correct

4. What was its angle relative to the horizontal (choose positive for above and negative for below)?

Not sure how to solve for this angle :(

Vector A has a magnitude of 15 m and makes an angle of 88deg with the positive x axis. Vector B also has a magnitude of 4 m and is directed along the negative x axis. Enter your answers in distance then angle(in degrees).

Find (A+B)

Find (A-B)

I have no idea how to even begin this problem... do you use the Pythagorean formula?

The pk of an acid is 4.16: Calculate the ph of a solution titrated with 63% NaOH .... I was doing the calculations and I got 4.39 but I was not sure if I just subtracted 63% or .63 from 100 to get the conjugate acid concentration [HA]? Can anyone help?