Watts Definition and 143 Threads

converting kg cal/hour into Watts? As the title suggests how should I go about converting kg cal/hour into Watts? Thanks

I am working on a project to consider how much air conditioning in a metropolitan area raises the temperature outside. I am trying to figure out how to translate the temperature outdoors (say 32 degrees C) into watts per square foot. Once I have the watts per square foot of heat already in the...

...than my current unit,is there danger that some component in my PC will be destroyed?

Homework Statement Hello, I am having some trouble with the two questions below: 1) The University of Maryland's mascot is a terrapin (a snapping turtle). It is represented on campus by a bronze statue in front of the library named Testudo. Unfortunately, students rub his nose for luck on...

Homework Statement What is the power output of a bodybuilder who raises 150kg from the ground to a height of 2.2m in 1.3 seconds? Express your answer in Watts and Horsepower (1hp=746w) Homework Equations show me how to do this problem The Attempt at a Solution show me how to do...

Homework Statement A pump is to lift 8.00 kg of water per minute through a height of 3.50 m. What output rating (watts) should the pump motor have? Homework Equations The Attempt at a Solution I have no idea how to even start.

Hi All, Could someone please help me with the calculations & an example of Watts consumed to Air Temperature rise in a given area: Eg: If we have a closed sealed container with no outside influences of area say 1 cubic meter, well insulated with an electrical heat source of the best...

Hi all, This is not homework, just theory discussion with my son. My son has been asking some interesting questions with regard to displacement as it relates to water. All kinds of teenager, “what if” stuff. I have looked around for simple formulas, but I am not embarrassed to say, I do not...

Help with units The book gives the following forumla E_0 = \sqrt {2\mu _0 c\left\langle S \right\rangle } And when it uses it in an example, the units go from: \sqrt {\left( {{\rm{H/m}}} \right)\left( {{\rm{m/s}}} \right)\left( {{\rm{W/m}}^{\rm{2}} } \right)} to V/m, with no intermediate...

Hi, I have a question regarding light, specifically artificial light. Please forgive me I am not a physics guru by any means and my terminology may be completely wrong, but hopefully someone will be able understand what I am trying to ask. First, the only way I know how to ask is in basic...

I have an oven and the heater element is ran by a watlow controller. It is going out evey two or three years. The watlow controller runs a relay to turn element on and off. The relay on the watlow needs a load of 100ma min. to keep contacts clean. I have the resistance of the coil for the on off...

Hi. How do you convert watts per metre squared to decibels? I know you use logs but can't seems to work it out. Thanks for any help.

Shown in the attachment is a system consisting of a heat pump and other components. My question is how I can approximate the total cooling effect in Watts available to the cooling battery. I know that the ground water is about 5 degrees, and I have some other data as well, just shout as I'm not...

Homework Statement how do you convert watts into ohms? Homework Equations The Attempt at a Solution

Homework Statement A steam iron draws 8.0 A when connected to a potential difference of 120 V. (a) What is the power rating of this iron? 960 W <<<<correct (b) How many joules of energy are produced in 20.0 min? 320 J <<<incorrect why? (c) How much does it cost to run the iron for...

Hello, I'm having problems with this question. I'm not exactly sure how to determine how much watts in a day, or in a second the lamp takes. Homework Statement Theres a lamp that absorbs 60 W when connected to a 120-V source. Q: Find the cost of operating the lamp for 24 hrs when...

[SOLVED] converting calories to watts HELP please I've tried this problem six times and this is what I keep coming up with. Any help would be greatly appreciated. I realize this is a very simple simple problem but why this is not working for me I do not know. Again Thank You very much for...

How might i convert the temperature in kelvins of a 1/2inch 2" x 2" steel plate when i have 28322 watts of sunlight focused on it for 5min? also if i am stating this question wrong i will be focusing 850 2" x 2" spots of sunlight on a single 2" x 2" surface how might i calculate the temperature...

An ice cube is placed in a microwave oven. Suppose the oven delivers 104 W of power to the ice cube and that it takes 32165 J to melt it. How long does it take for the ice cube to melt? Following my lecture notes and my textbook ... the formula should be t=(J/W), but that isn't giving me...

Homework Statement How to calculate Lance Armstrongs power output/calorie consumption at 30 mph, 125 miles on level ground , no wind, 157 lbs plus 16lb bike? Homework EquationsWhat equations do I use? The Attempt at a Solution I'm 14 years old, where do I start

Hello All, This is an edited re-posting. I am looking for verification on a formula. As part of a personal design project (not for school or homework) I’m designing coils of magnet wire (i.e. coils in a generator) and I have all of the computational resources I need, with the exception of a...

Homework Statement I am looking for a conversion factor that will ultimately get me from units of lux (illumination) which is a weighted scale of light intensity, to watts per square meter, which is not weighted. Homework Equations None availiable The Attempt at a Solution I am...

Greetings All, I'm restarting a personal project (after having to put it on hold) involving magnetically induced electricity and I'm trying to stay within the wire manufacturer temperature tolerance specs. I know the formula (P = I^2*R) for figuring out how much heat will be dissipated by a...

Colombs,Amps,Volts,and Watts. HELP! Homework Statement A given car battery is rated at 250 amp-hours. Does this rating indicate the amount of energy, power, charge, voltage, or current that can be drawn from the battery? Explain. Homework Equations Coulombs, Amps, Volts, Watts. The...

If some appliance needs let's say 500 Watts to run, does that automatically mean that it also produces 500 Watts worth of heat to its surroundings? Or would that be an indication that it's hopelessly inefficient?

Homework Statement A 20 ohm platinum wire at 20 C with a temperature coefficient of resistivity of 3.9 x 10 ^-3 /C will have what resistance at 100 C? I know how to answer this in watts and I get 26 W, but for some reason my only options are in ohms. how do i convert Watts to ohms? i...

This is my (error full?) understanding from my readings: 1. positive current flowing into a positive terminal of let's say a rechargeable battery is power being absorbed by the battery...so positive watts 2. negative current flowing into a positive terminal encounters the higher electrical...

I am in grade 11 physics and haven't yet learned about thermodynamics or anything dealing with heat really. I am wondering basically if you can reliably measure the power difference between two settings on a stove through temperature. i.e use a thermometer, measure the temp of the element at...

Homework Statement its a long story problem so ill break it down: an electric heater generates 250 Watts of electricity, how long will it take for 250 grams of water to heat from 20 C to 80 C The Attempt at a Solution so 80 C - 20 C = 60 C , i have to heat it 60 C 250 grams of water...

I have a problem where I have a cup of water and I have to find out how much power I need to generate to heat it by a certian amount. I can't seem to find the equation I need in my book, can someone help me out? thanks.

how many watts does the human body use i guess 500w

not sure how to solve this, having trouble finding the equation I need in my book. any help is appreciated. thanks in advance. A 60 kg woman runs up a flight of stairs having a rise of 4.0 m in a time of 6.0 s. What average power did she supply?

hi can i connect two amplifires to one speaker. i have sony amplifire 500 watts and JBL amplifire 600 watts. and two speakers 800 watts. Q i want to connect the two amplifires to give me 1100 watts to look like one amplifire. thanx

I tried to figure out how many watts a person runs on who eats a 2,000 calorie diet. First, dietary calories are really kilocalories, so someone eating a 2,000 calorie diet is really eating 2,000,000 calories. 1 calorie is 4.184 joules, so multiply 2 million by 4.184 and you get 8,368,000...

-------------------------------------------------------------------------------- A pump is to lift 29.0 kg of water per minute through a height of 3.70 m. What output rating (watts) should the pump motor have? An airplane pilot fell 380 m after jumping without his parachute opening. He...

hi, i have another question i can't get, the problem is: We want to boil one liter of water in a light thin-walled vessel. For this purpose, we start to heat water by an electric heater, with the label "500W. Made in Wonderland". However, after the temperature becomes 60*C, it stops...

I have a 300 kg piano being lifted at a steady speed from the ground to a hieght of 10 meters and the crane that is doing the lifting is providing 400 watts of power. How much time does it take to get the piano to the top. So far I have Power = work/Time so time is Work/ power , so, work is...

I thought watts was defined as J/sec . So how can something be rated in watts/hour? Doesnt that mean Joules per second per hour?

Units -- Watts, meters & Kelvin I have an equation: L = \sigma T^{4} * 4 \pi R^{2} Which I fill with values and units L=5.67*10^{-8} * (5860K)^{4} * 4 \pi * (6.96*10^{8}m)^{2} and I get an answer: 4.07*10^{26} K^{4} m^{2} The correct answer is: 4.07*10^{26} watts I don't...

Watts per squ meter?

Root mean square. The square root of the sum of the squares of a set of quantities divided by the total number of quantities. Used when monitoring ac (alternating current) signals. Many power supplies, for example, issue an ac signal. This needs to be converted to a dc (direct current) signal...

A pump is to lift 16.0 kg of water per minute through a height of 3.38 m. What output rating (watts) should the pump motor have? Potential Energy Initial = O Kenetic Energy Final = 0 So, KE-PE = W 1/2mv^2 - mgh = Work 1/2(16.0)(3.38)^2 - (16.0)(9.8)(3.38) = -439 W The fact that my...

Let's say, for example, that I have a common household item that is 6amps, being run from a 12v circuit, like a car battery. That would make the wattage 72, correct? What is the time frame on that? Is that 72 watts an hour? a minute? Basically, how do I convert that number, 72watts, into a...