Sejul

Most popular questions and responses by Sejul
1. physics

an oil drop has a charge of 8.0 x 10^-19 C. How many excess electrons does the oil drop have?

2. Maths

Grandpa places money in an account on your first birthday and will place that same amount in the account every year, ending with your 18th birthday. So there is a total of 18 deposits starting on first birthday. He expects to earn 8% interest per year. How

3. physics

person weighs 526 N on Earth. Another planet has twice the mass of Earth and Twice the radius of Earth. Find the weight on the other planet. I need help with a formula too.

4. Physics

A 3.70kg box is sliding across the horizontal floor of an elevator. The coefficient of kinetic friction between the box and the floor is 0.470. Determine the kinetic frictional force that acts on the box when (a) The elevator is stationary. (b) The

5. physics

a .20 kg ball on a string is whirled on vertical circle at constant speed. When the ball is at 3:00 position, tension is 16 N. a) is centripetal force acting on ball the same at each point on the circle? b) when the ball is at 3:00, what is proving the

A 3.70kg box is sliding across the horizontal floor of an elevator. The coefficient of kinetic friction between the box and the floor is 0.470. Determine the kinetic frictional force that acts on the box when (a) The elevator is stationary. (b) The

7. physics

A 20. kg block is placed at the top of a 10. meter-long inclined plane. The block starts from rest and slides without friction down the length of the incline. (A diagram shows a height of 5.0 m, the 10. m length of incline/hypotenuse and the 20. kg block

8. math

open top rectangular box made from 35 x 35 inch piece of sheet metal by cutting out equal size squares from the corners and folding up the sides. what size squares should be removed to produce box with maximum volume.

9. trig

I have to retype this. For which angles theta, with 0 degrees less than/equal to theta less than/equal to 180 degrees, is sin 3theta = (equal) -1 (negative 1)? a) 30 and 150 degrees b) 60 and 120 degrees c) 90 degrees d) 0 and 120 degrees How do I set this

10. Physics

Soccer player kicks a ball down field. The ball's initial velocity is 30 m/s, 30 degrees above horizontal. a) What is the ball's horizontal velocity at the maximum height of the ball's trajectory? b) What is the horizontal displacement of the ball just

11. physics

if one resistor is removed from a parallel circuit, the total current will 1) decrease b) increase c) remain the same and the current flowing through each of the remaining branches ____________________. removing one resistor makes total resistance greater.

12. math

distribution of adjust gross income in individual federal income tax returns shows: Income: 30-74, 75-199, more than 200 Probability: 0.315, 0.180, 0.031 1. What is the probability that a randomly chosen return shows an adjusted gross income of \$30,000 or

13. physics

German silver wire has a cross-sectional area of 2.047 x 10^-3 cm^2. How many meters are needed to make a resistance of 100 (omega)? I can't find the resistivity of German silver wire. I've googled a few places, but each one gives me a different number.

The difference in potential between any two points in a field is the ___ required to move a unit of whatever is affected by the field between the two points. I need help with this. Could it be work? or energy? Please help

15. physics

Through the process of doing work, energy can move between the external world and the system as the result of ____. The sentence is completed with the word FORCES. You have to rewrite the word to make the sentence true (if it is not already true.)

16. Physics

A projectile of mass 1.350 kg is shot straight up with an initial speed of 22.0 m/s. (a) How high would it go if there were no air friction? (b) If the projectile rises to a maximum height of only 17.8 m, determine the magnitude of the average force due to

17. physics

in an experiment using Coulomb's apparatus, a sphere with a charge of 3.6 x 10^-8 C is 1.4 cm from a second sphere of unknown charge. The force between the spheres is 2.7 x 10^-2 N. What is the charge of the second sphere? I get 1.3 x 10^-4 C, but the

18. physics

I need to know the resistivity of german silver wire. I've looked at a few Google sources and I've seen several different results. Anyone know which value I should use?

19. Chemistry

Calculate the amount (g) of each of the following salts that need to be added to a 200 mL volumetric flask to produce a 2 M solution of S. CaSO(subscript 4) [NH(subscript 4)subscript 2]SO(subscript 4) NOTE: the subscript 2 is outside the (NHsubscript 4)

20. physics

a 2.5 kg rifle fires a 20 g bullet at 400 m/s. What is the magnitude of the recoil velocity of the rifle? I still don't understand. Could you please help with a formula? Thank you. physics - drwls, Monday, February 7, 2011 at 6:38pm Try using conservation

21. Maths

Mortgage company lets you pay a point (1% of total amount of loan)to reduce APR from 6.5% to 6.25% on a \$400,000 30-yr mortgage with monthly payments. Plan to be in house for at least five years. Should you pay the point?

22. math - regression line - thank you

The question states: Plot the regression line from D = 40 to D = 300. My question: Do you extend the line beyond those 2 points (as in going towards the axis) or does the regression line just connect those 2 points like a line segment? Thank you

23. math

How many pounds of water are in a 36 ft diameter tank that is filled to a depth of 24 ft? Thank you.

24. algebra

have 50 sq ft of material to make an open top box with a square base. a) use formula for surface area to express the height h of the box in terms of x. b) find the dimensions of the box that will produce the maximum volume.

25. physics

if one resistor is removed from a parallel circuit, the total current will 1) decrease b) increase c) remain the same and the current flowing through each of the remaining branches ____________________. removing one resistor makes total resistance greater.

Although I vaguely see DrBob222's concept, I still need some help in the set up. Thank you. A 10 lb. frozen boneless roast needs to be thawed and baked to a temperature of 200 degrees F. The storage freezer maintains a temperature of -10 degrees F. Pork

27. Physics

When a parachute opens, the air exerts a large drag force on it.This upward force is initially greater than the weight of the skydiver and, thus, slows him down. Suppose the weight of the skydiver is 956 N and the dragforce has a magnitude of 1005 N. The

28. math logs

solve 3^(2x+1) = 9^(2x-1) using base 3 logs

29. math

radiators sell for \$350. Let x be radiators. profit shown by equation p= -.01x^2 +375x -600,000. What number of radiators will produce the larget possible profit? What is the largest possible profit?

30. Algebra

An open box is to be constructed from a rectangular sheet of tin 3 meters wide by cutting out a 1-meter square from each corner and folding up the sides. The volume of the box is to be 2 cubic meters. What is the length of the tin rectangle?

31. physics

if one resistor is removed from a parallel circuit, the total current will 1) decrease b) increase c) remain the same and the current flowing through each of the remaining branches ____________________.

32. physics

A 20. kg block is placed at the top of a 10. meter-long inclined plane. The block starts from rest and slides without friction down the length of the incline. (A diagram shows a height of 5.0 m, the 10. m length of incline/hypotenuse and the 20. kg block

33. physics

I need formula/problem set ups for the following 2 problems: 1)Find The work done by the force in pulling an object on an inclined plane from A to B (ground level to top): Length of incline (like a hypotenuse): 30 m Height of incline (y axis): 10 m Force =

34. physics

Two girls each weight 500 N. Ride in a car traveling at 20.0 m/s. One wears a seat belt. The other does not. In an accident the girl wearing the seat belt is brought to a stop in 0.120 seconds. The dashboard brings the other one to a stop in only 0.00800

35. chemistry - Can you please check

Calculate the amount (g) of each of the following salts that need to be added to a 200 mL volumetric flask to produce a 2 M solution of S. CaSO4 (NH4)2SO4 Fe2(SO4)3 Dr. BOB222, Could you please check the following? Thank you. CaSO4: moles x atomic mass =

36. algebra

A man has 400 meters of fencing and wants to fence in a rectangular field next to a straight river. Assuming that no fencing is needed along the river, what are the dimensions of the field with the largest possible area?

True or false: 2 ln x / ln 5 = ln x^2 - ln 5 for all positive values of x.

38. algebra

For every point (x,y) on the graph y = 30 - 5x^2, consider a rectangle with corners (-x, 0), (-x,y), (x,0), and (x,y). For which value of x does the rectangle have a maximum area?

39. algebra

length of rectantular rug is 7/6 its width. rug is placed on floor with 1 foot margin all around. area of floor is 4 times that of margin. find the dimensions of the room.

40. algebra

Can you use algebra to find a quadratic equation if your know the coordinates of just ONE point on its graph? Can you use algebra to find a quadratic equation if your know the coordinates of just TWO points on its graph? If so, what information is needed?

41. physics

inserting a resistor in series with a combination of two or more resistors in parallel will ___ the voltage across the parallel circuit

42. Physics

German silver wire has a cross-sectional area of 2.047 x 10^-3 cm^2. How many meters are needed to make a resistance of 100 (omega)? I don't know where to begin.

43. Physics

If a pointer on a spring scale moves 0.0254 m when a 2.224 N weight is fastened to the hook, the pointer will move how many m when a 17.79 N weight is used?

65 chemical engineering students are from urban/suburban backgrounds. (Success is defined as a C or better in the course.) 52 of the 65 students succeeded. Another 55 students were from rural backgrounds; 30 of these students succeeded. A Is there good

45. math

The question states: Plot the regression line from D = 40 to D = 300. My question: Do you extend the line beyond those 2 points (as in going towards the axis) or does the regression line just connect those 2 points like a line segment?

46. algebra

In a circle with radius of 7 cm, an arc of the circle has length 22 cm. The central angle theta is ??

47. Physics

if one resistor is removed from a parallel circuit, the total current will 1) decrease b) increase c) remain the same and the current flowing through each of the remaining branches ____________________. okay so the total current will decrease, but what

48. physics

Electric power is found by multiplying ___ by current. Is voltage or potential difference a better choice to use?

49. physics for Mr. Pursley

I see 18% Nickel Alloy A (under pure silver) is listed as 2.874 x 10^-7 Is this what I should use?

50. physics

Through the process of doing work, energy can move between the external world and the system as the result of ____. The sentence is completed with the word FORCES. You have to rewrite the word to make the sentence true (if it is not already true.)

51. physics

a 2.5 kg rifle fires a 20 g bullet at 400 m/s. What is the magnitude of the recoil velocity of the rifle?

52. Math/physics

An 6 x 8 wood column is 17 feet tall and is loaded with 40 Kips. Will it buckle (K = 1.0)? How do I set this up and solve? Please show steps. I am confused and do not know how to start. Thank you.

53. Physics

Find the moment of inertia of the following "L" shape about the x-x axis (I sub x) The base of the L shape is 4 inches long and 2 inches high. The vertical column of the L shape is 8 inches high and 2 inches wide. (So the "block L" is 2 inches wide

54. math

random sample of 9600 students. 46% had at least one parent who was a college graduate. Estimate with 99% confidence the proportion of all students who had at least one parent who was a college grad. b) Sample does not include drop outs so estimate is

55. Science

A 10 lb. frozen boneless roast needs to be thawed and baked to a temperature of 200 degrees F. The storage freezer maintains a temperature of -10 degrees F. Pork changes from solid to a thawed state at 30 degrees F and has the following properties: Heat

56. physics

Electric power is found by multiplying ___ by current. Is voltage or potential difference a better choice to use?

57. math

For which angles beta, with 0 degrees less than/equal to beta less than/equal to 180 degrees, is sin 3beta equal to -1? a) 30 degress and 150 degrees b) 60 and 120 degrees c) 90 degrees d) 0 and 120 degrees I think it is C because sin of (3 x 90 = 270) 270

58. trig

For which angles ¦È, with 0¡ã ¡Ü ¦È ¡Ü 180¡ã, is sin 3¦È = -1? How do I set this up?

59. physics

a 2.5 kg rifle fires a 20 g bullet at 400 m/s. What is the magnitude of the recoil velocity of the rifle?

60. physics

charging by induction creates charge by transferring charges from one object to another OR separates charges within an object

2. Tu dessines 4. Elle peut marcher. 5. Nous pouvons frapper.

posted on September 14, 2013
2. chemistry - Can you please check

I'm confused again. Can you show me how to get the CaSO4 so I can do the other two? What did I do wrong? I showed you my work. I thought I followed your instructions from Saturday. You said I needed a number near 13. I got the 12.8264. If you could please

posted on January 23, 2013
3. Chemistry

Dr. Bob222, Could you please check the following? Thank you. CaSO4: 54.45664 g (NH4)2SO4: 12.8264 x 132.1402/32.066 (molar mass(NH4)2SO4/atomic mass S)= 52.85608 g Fe2(SO4)3: 12.8264 x 399.8801/32.066 (molar mass Fe2(SO4)3/atomic mass S)= 159.95204 g Thank

posted on January 21, 2013

Thank you so much for your help.

posted on January 28, 2012
5. physics

okay so the total current will decrease, but what about the second part? and the current flowing through each of the remaining branches ____. remains the same????

posted on May 18, 2011
6. physics

I see 18% Nickel Alloy A (under pure silver) is listed as 2.874 x 10^-7 Is this what I should use?

posted on April 28, 2011
7. physics

Two girls each weight 500 N. Ride in a car traveling at 20.0 m/s. One wears a seat belt. The other does not. In an accident the girl wearing the seat belt is brought to a stop in 0.120 seconds. The dashboard brings the other one to a stop in only 0.00800

posted on February 4, 2011