Physics - November 2006

2006-11-20 14:24:58 · 10 answers · asked by Anonymous

2006-11-20 13:56:47 · 8 answers · asked by fatima_hassanien 1

A gardener pushes a 18 kg lawnmower whose handle is tilted up 35° above horizontal. The lawnmower's coefficient of rolling friction is 0.15. How much power does the gardener have to supply to push the lawnmower at a constant speed of 1.4 m/s?

Any thoughts?


Thanks!
Any suggestions?

2006-11-20 13:52:12 · 3 answers · asked by Anonymous

A 20 kg box was given a push and is sliding along a table with a coefficient of friction of 0.4.



What is the net force acting on the box?

What is the acceleration of the box?


please help!! thank you .

2006-11-20 13:51:21 · 4 answers · asked by lex 1

2006-11-20 13:44:56 · 6 answers · asked by Lanie 1

A beam of light in air strikes a piece of glass at an angle of 40 degrees. What is the index of refraction for the glass if the refracted angle is 25 degrees?

I know the answer is 1.52. I need to learn how to solve it and show the work in details. Please help me out. Thanks.

2006-11-20 13:44:44 · 3 answers · asked by eternal.diamonds 1

please be brief in answering but accurate. please and thank you.

2006-11-20 13:43:25 · 4 answers · asked by Anonymous

please be specific but brief. please and thank you.

2006-11-20 13:42:08 · 4 answers · asked by Anonymous

know how to caculate capacitance in parallel and series, but I'm not sure I truly understand exactly what capacitance IS. I know that a capacitator stores electricity until a certin point, then releases it all at once. But why do we want that? How is it useful besides making sirens?

I also know that a numberline is formed with resistance as the positive values, zero as perfect conductance and capacitance as the negitive numbers. Does that mean that capacitance is a kind of anti-resistance? Is a circut with just a capacitor somehow have negitive resistance?

2006-11-20 13:36:26 · 2 answers · asked by metaphysics1221 2

I know the answer is 5.4054 x 10^14Hz. I need to know how to get it and I need you to show the work in detail. Please help me out. Thanks.

2006-11-20 13:32:28 · 3 answers · asked by eternal.diamonds 1

I am doing a calculation on equivalent resistance of a parallel circuit:

(1/nΩ) means 1 over nΩ
(Req) means Equivalent Value

R1 =6
R2 =6 Ω
R3 =6 Ω

1/Req = 1/R1 + 1/R2 + 1/R3
1/Req = 1/R1 + 1/R2 + 1/R3
1/Req = 1/6 Ω + 1/6 Ω + 1/6 Ω
1/Req = 3/6 Ω
1/Req = 1/2 Ω


**After 1/Req = 1/2Ω, I dont know what to do to make the left side: become Req and the right side become just the value of an ohm.**

2006-11-20 13:19:00 · 2 answers · asked by Anonymous

Truck brakes can fail if they get too hot. In some mountainous areas, ramps of loose gravel are constructed to stop runaway trucks that have lost their brakes. The combination of a slight upward slope and a large coefficient of friction in the gravel brings the truck safely to a halt. Suppose a gravel ramp slopes upward at 5.0° and the coefficient of friction is 0.48. Use work and energy to find the length of a ramp that will stop a 17,000 kg truck that enters the ramp at 35 m/s (75 mph).

I tried using the 1/2mv^2 + f(dx) = 1/2m(vcos(theta))^2 + mgh and I seem to be getting about 717 meters, which is wrong. I think I am finding dx wrong. How do you calculate dx? Is the equation right in the first place?

Thanks!

2006-11-20 12:59:28 · 1 answers · asked by Anonymous

If you were traveling at the speed of light, would the light be in front of you, behind you or would there be none at all?

2006-11-20 12:57:25 · 8 answers · asked by Anonymous

What volume V of helium is needed if a balloon is to just lift a load of 800 kg.? This number includes only the load and the weight of the empty balloon. Note the density of air is 1.29 kg/m cubed and the density of helium is 0.18 kg/m cubed.
Cool if you could include the math as to how you figured this out! Thanks

2006-11-20 12:56:44 · 3 answers · asked by Anonymous

They leave from the same point at the same time and travel at the same speed. Does the fact the bus wheels are bigger than the motorbike's make the bus arrive first?

2006-11-20 12:46:09 · 7 answers · asked by Marcelo A 1

2006-11-20 12:42:08 · 1 answers · asked by veryberry 3

in science i need to make a postor of the two types of heat tranfer..ive been absent so what picture could i draw for raditaion and what for conduction?
ps: it has to be and object

and also can someone please define conduction and radiation?

2006-11-20 12:16:32 · 3 answers · asked by dfgfdg f 1

Please help with this, i haven't gotten straight answers, ive gone halfway and im stuck, here's the question:


Consider a massless cord attached at both ends to hooks in a ceiling. A 20-kg mass is then suspended from the first cord by a second cord. The angles made by the cord with the ceiling are 40 degrees (left angle) and 25 degrees (right angle). Find the tension in each cord.


here are the two equations ive got

T1(.64) + T2(.42) = 0

and

T1(.77) + T2(.91) = 0

and im stuck

2006-11-20 12:10:30 · 4 answers · asked by sur2124 4

2006-11-20 12:03:41 · 5 answers · asked by lisaloulou6969 2

A temperature controller that keep the temperature of liquid constant between 50 to 80 degree celsius

2006-11-20 11:49:58 · 2 answers · asked by thonjela 1

Inventories Link Outward Values Eventually Secrets Are Mild Mixtures In Earth

2006-11-20 11:38:40 · 2 answers · asked by yoanna 2

this is the starting for my paragraph i have lots more to put in it but i just want a lil somin about effort

A levver is made up of three things. A fulcrum, wich is the pivot or support on wich, a lever turns in raising or moving something. Then there is the effort. The effort....... this is where i need to talk about effort

2006-11-20 11:38:00 · 1 answers · asked by bball_plyr_11 2

the penny-farthing is a bicycle that was popular between 1870 and 1890. On a Sunday ride in the park the front wheel (radius = 1.20 m) makes 192 revolutions. How many revolutions does the rear wheel (radius = 0.340 m) make?

2006-11-20 11:34:17 · 1 answers · asked by cosmos 1

the climate near big bodies of water usually is more moderate(warmer) than the ones that are far from bodies of water, why does this happend? what does the water has to do here?

2006-11-20 10:45:41 · 10 answers · asked by Jandro 1

A block of mass 2.50 kg is pushed 2.40 m along a frictionless horizontal table by a constant 18.0 N force directed 25.0° below the horizontal.
(a) Determine the work done by the normal force exerted by the table.
(b) Determine the work done by the force of gravity.
(c) Determine the work done by the net force on the block.
Please Show your work. Thank You Very Much!!!!!!!

2006-11-20 10:38:37 · 3 answers · asked by Tennis2127 2

A canteloupe is rolled off the edge of a building roof with a velocity of 5.4m/s. It reaches the ground in 3 seconds. How high is the building? How far away from the base of the building does the canteloupe land? What happens to the canteloupe?

2006-11-20 10:38:09 · 2 answers · asked by Daniel 1

And also at a few feet apart - what would happen when the bullets met?

2006-11-20 10:26:47 · 7 answers · asked by This is my username 3

A car is coasting down a hill, gaining energy as it goes. As they near a stop sign, the driver begins lightly pressing on the brakes. Where does the energy they gained from coasting down the hill go?

2006-11-20 10:15:17 · 6 answers · asked by BadRomance 2

2006-11-20 10:11:12 · 1 answers · asked by kavita s 1

If so, could matter moving faster than the speed of light enter the event horizon and exit in an arch and never enter the same black hole again?

2006-11-20 10:07:27 · 5 answers · asked by merviedz trespassers 3