Physics - January 2007

in an DC circuit how can I obtain -48V

2007-01-19 19:16:42 · 4 answers · asked by george g 1

2007-01-19 19:14:28 · 6 answers · asked by Anonymous

grains of fine california beach sand are approximately spheres with an average radius of 50 um (micro-meters = 10^6) and are made of silicon dioxide. A solid cube of silicon dioxide with a volume of 1.00 m^3 has a mass of 2600 kg. what mass of sand grains would have a total surface area(the total area of all the individual spheres) equal to the surface area of a cube 1.00m on an edge?

2007-01-19 19:11:41 · 2 answers · asked by mathlover 2

2007-01-19 19:02:30 · 4 answers · asked by dayah_2111 1

2007-01-19 18:53:00 · 14 answers · asked by SaRa 2

2007-01-19 18:39:11 · 6 answers · asked by Gideon 1

What's the difference between paparllel and series connection?

2007-01-19 18:31:30 · 8 answers · asked by Anonymous

A 4.00 x 10^2-g glass coffee cup is at room temperature, 20.0ºC. It is then plunged into hot dishwater, 80.0ºC. If the temperature of the cup reaches that of the dishwater, how much heat does the cup absorb? Assume the mass of the dishwater is large enough so its temperature doesn't change appreciably.

2007-01-19 17:19:15 · 3 answers · asked by smiyololo 1

remain in that position unless the driver stop putting breaks??

2007-01-19 17:03:38 · 11 answers · asked by Anonymous

A basketball player, about to "dunk"the ball,jumps 76cm vertically. HOw much time does the player spend (a) in the top 15cm of this jump and (b) in the bottom 15cm? Does this help explain why such players seem to hang in the air at the tops of their jumps?

2007-01-19 16:59:56 · 3 answers · asked by Anonymous

2007-01-19 15:53:50 · 7 answers · asked by Maria; 2

Why is it so easy to roll a ball or a wheel and yet so much more difficult to slide a block along the floor? What is the difference?

2007-01-19 15:41:36 · 11 answers · asked by califrniateach 4

2007-01-19 15:34:55 · 14 answers · asked by vikramgoodboy 1

please give me comparisons or measurements.... anything, thanks

2007-01-19 15:18:37 · 11 answers · asked by Anonymous

what store would sell a voltmeter? it's for my science project.
do any of you know what kind of store sell that?
ex) fred meyer, cost-co.. or etc.

2007-01-19 14:27:33 · 6 answers · asked by JJ 1

In 39 s ; a pump delivers 0.619 dm^3 of oil
into barrels on a platform 39 m above the
pump intake pipe. The density of the oil is
0:832 g/cm3 :
The acceleration of gravity is 9.8 m/s2 :
Calculate the work done by the pump. An-
swer in units of kJ.
part2
Calculate the power produced by the pump.
Answer in units of kW.

2007-01-19 14:17:37 · 3 answers · asked by kavita 1

Rosie (mass 59 kg) pushes a box with a hor-
izontal force of 150 N (33.72 lb) at a speed
16 m/min. What is Rosie's power output?
Answer in units of W.

2007-01-19 14:16:10 · 3 answers · asked by kavita 1

6. part1
A 1970 kg car accelerates uniformly from rest
to a speed of 17.3 m/s in 3.72 s.
Find the work done by the net force on the
car during this time interval Answer in units
of J.
part2
Find the average power delivered by the net
force to the car in this time interval. Answer
in units of w.
part3
What is the instantaneous power delivered by
the net force to the car at 2 s? Answer in
units of w.

2007-01-19 14:15:10 · 1 answers · asked by kavita 1

A bicycle wheel has an initial angular velocity of 1.50 rad/s. a) if its angular acceleration is constant and equal to 0.300 rad/s^2.What is the angular velocity at t=2.50 s? b.) through what angle has the wheel turned between t=0 and 2.50 s ?

2007-01-19 13:42:36 · 6 answers · asked by jhen_hidaka 1

question....please help me

At t=0 the current to a dc electronic motor is reversed resulting in an angular displacement of the motor shaft given by theta(t) = (250 rad/s)t - 20 rad/s^2)t^-(1.50 rad/s^3)t^3.
a.) at what time is the angular velocity of the motor shaft zero? b.) CAlculate the angular acceleration at the instant that the motor shaft has zero angular velocity. c.) How many revolutions does the motor shaft turn trough between the time when the current is reversed and rhe instant when the angular velocity is zero? d.) How fast was the motor shaft rotating at t=0,when the current was reversed?

thanks really for the help.:)

2007-01-19 13:25:35 · 3 answers · asked by ice_cream_chico11 1

2007-01-19 13:17:46 · 10 answers · asked by Hannah D 1

ok. joseph is riding in an elevator which is accelerating downward at -20 meters per second squared. by summing the vertical forces, find the magnitude of the force that the cailing is exerting on joseph if he has a mass of 82 kg.

2007-01-19 13:17:23 · 7 answers · asked by judykharrison 1

the grinder was supplied with 22,486.1 watts of power. the grinder's fractional efficiency was .008. find the work done by the machine in 185 seconds.

2007-01-19 13:15:19 · 2 answers · asked by judykharrison 1

debra pushes the 25 kg box across the floor with a force of 134 newtons. find the magnitude of the acceleration of the box if the coeffiecient of kinetic friction between the box and the floor is .32 .

2007-01-19 13:13:35 · 3 answers · asked by judykharrison 1

If the principal quantum number of a shell is equal to 2, what types of orbitals will be present? Is it s and p, or just s? Also, if the principal quantum number of the outermost electron of an atom in the ground state is n=3, what is the total number of occupied principal energy levels contained in the atom? Is it 1, 2, 3, or 4?

2007-01-19 13:05:27 · 2 answers · asked by Anonymous

find the dp/dt at the boiling point.

2007-01-19 13:00:18 · 1 answers · asked by joy 1

A measurement of its thermal capacity inside a container having the constant volume 100 liters shows that under these conditions ,the thermal capacity is constant and equal to 0.1 cal./deg.Express the energy and the enthropy of the system as a function of T and V.

2007-01-19 12:55:07 · 1 answers · asked by joy 1

(assume a constant specific heat =1cal./gm.deg.)

2007-01-19 12:48:03 · 1 answers · asked by joy 1

to extract one calorie of heat from a body at the temperature of 0 F,when the temperature of the enviroment is 100 F.

2007-01-19 12:42:44 · 1 answers · asked by joy 1

2007-01-19 12:37:58 · 20 answers · asked by leslie_pisoo 1