Jessie L

Is it legal in LA to park an eighteen wheeler on a residential street? Coming home late one night, a friend of mine ran into an eighteen wheeler and wrecked her car. She went to the hospital right after due to a broken foot. She tried to contact the police to report the accident but the specific officer she needed to speak with was out until Monday. She is wondering who is at fault but it's my opinion the 18 wheeler is. Any advice?

The average high school principal works an average of 52 hours a week with a standard deviation of 2.6 hours. If we assume a bell-shaped distribution, what percentage of of principals works less than 49.4 hours a weeks? What percentage works more than 57.2 hours a week?

1] It has too many neutrons, and it decays with a half-life of about 29 yr. How long will we have to wait for the amount of [90]Sr[38] on the Earth's surface to reach 1% of its current level, assuming no new material is scattered about?

______________ years

2] Write down the decay reaction, including the daughter nucleus.

[90]Sr[38] --> (___) Element (__) + (___) (___) e + v

3] The daughter is radioactive: write down its decay.

The activity of a sample drops by a factor of 10 in 8.0 minutes. What is its half-life?

_______________ min

A radioactive material produces 1280 decays per minute at one time, and 6 h later produces 280 decays per minute. What is its half-life?

______________ h

(a) What is the decay constant of an isotope whose half-life is 5.20x10^9 yr?

Answer needs to be in this unit: s-1

This is my work so far:

.693/(5.2x10^9)= 1.33269231e-10 but this is to yr^-1

So really this is a conversion problem. I was thinking that I would times this by 365 days x 24hrs x 60 mins x 60 seconds to get .00420002 but this is wrong.

Help please.

A 1400 nF capacitor with circular parallel plates 1.0 cm in diameter is accumulating charge at the rate of 26.0 mC/s at some instant in time. What will be the magnitude of the induced magnetic field 10.0 cm radially outward from the center of the plates?

A 5.1 MeV (kinetic energy) proton enters a 0.17 T field, in a plane perpendicular to the field. What is the radius of its path in meters?

Suppose that you have a 330 ohm, a 680 ohm , and a 1.10 k resistor.

(a) What is the maximum resistance you can obtain by combining these?

I calculated this by adding .33 kohms + .68 kohms+ 1.1 ohms

This equlas 2.11 kohms.

(b) What is the minimum resistance you can obtain by combining these?

I have no formula to calculate the minimum. Can anyone help me out?

This answer should be in OHMS, not k ohms.

What is the net resistance of the circuit connected to the battery in Fig. 19-41? Each resistance has R = 1.8 k.

Click on the link below. It will bring up the figure of 19-41. There are 12 V in this problem.

http://i24.photobucket.com/albums/c39/immeteen/19_...

A power station delivers 510 kW of power at 12,000 V to a factory through wires with total resistance 3.0 ohms. How much less power is wasted if the electricity is delivered at 47,000 V rather than 12,000 V?

I asked this question earlier yet the formulas given to me in the answers did not yield the correct solution. More help pls

A 0.90 mm diameter copper wire carries a tiny current of 5.5 µA. What is the electron drift speed in the wire?

Speed should be in m/s.

A power station delivers 510 kW of power at 12,000 V to a factory through wires with total resistance 3.0 . How much less power is wasted if the electricity is delivered at 47,000 V rather than 12,000 V?

A certain copper wire has a resistance of 9.8 . At what point along its length must the wire be cut so that the resistance of one piece is 6.0 times the resistance of the other?

1/5 of the length

1/6 of the length

1/7 of the length

****Here I have determined that 1/7 of the length is the correct answer as follows:

6x=L-x

7x=L or 1/7

The book does not give formulas or have similar problems of the following. Help with formulas and calculations would be greatly appreciated.

What is the resistance of each piece?

A) larger piece

B)smaller piece

A +30 µC charge is placed 54 cm from an identical +30 µC charge. How much work would be required to move a +0.60 µC test charge from a point midway between them to a point 8 cm closer to either of the charges?

I'm really just looking for the formulas and/or steps to get to the solution and not just the solution. Thanks

Needing some help on this problem....My book has no similar problems and I can't find any like this in my notes so I'm lost completely. Help please!

Calculate the electric potential due to a dipole whose dipole moment is 4.3 x10-30 C·m at a point 1.8 x10-9 m away if this point is at the following locations.

A)along the axis of the dipole nearer the positive charge

B) 45° above the axis but nearer the positive charge

C)45° above the axis but nearer the negative charge

What are the magnitude and direction of the electric field at a point midway between a -8.0 µC and a +5.0 µC charge 3.5 cm apart? Assume no other charges are nearby.

Find the magnitude!

I've asked this question before showing my work and was given two answers on why my answer was wrong. Neither one was correct so I am resubmitting my question without my work. I was thinking a fresh start minus my work may produce the correct answer? Thnx.

I have a triangle. Here's the pic to help out:

http://i24.photobucket.com/albums/c39/immeteen/tri...

I found the magnitude by doing the following:

distance=1.1 meters

q1= 4.0 uC

q2= -10.uC

q3= -6.0uC

magnitude = (kq1)/(d^2) x [ q2^2 + q3^2 + (2 x (q2)(q3)(cos 60)]^1/2

magnitude= .4165

Now here's where I run into trouble:

direction = tan(-1) (q3 sin 60)/(q3 cos 60 + q2)

tan(-1) = (6.0x10^-6 x sin 60) / (6.0x10^-6 cos 60 + 10x10^-6)

= (5.196 x 10^-6)/(1.3 x 10^-5)

= inverse tan of .3997

= 21.78 degrees. Yet this is WRONG. HELP! PLEASE!

A flat circle of radius 18 cm is placed in a uniform electric field of magnitude 5.1x10^2 N/C.

b) What is the electric flux through the circle when its face is at 40° to the field lines?

Equation:

=EA cos ()

E=5.1x10^2

A=pi x .18^2 = .102

angle=40 degrees

(5.1x10^2)(.102)(cos 40)

=39.84

Yet it is wrong. What am I doing wrong?

What are the magnitude and direction of the electric field at a point midway between a -8.0 µC and a +5.0 µC charge 3.5 cm apart? Assume no other charges are nearby.

FIND MAGNITUDE:

Equation:

E=(k/r^2)(absolute value q1 + absolute value q2)(10^-6)

plug in numbers:

E=(9.0x10^9/.035^2)(8+5)(10^-6) = 95510204.08 N/C