physics

Question 83723 asked on 2011-08-20 15:06:40

Mechanical efficiency (ME) is defined as the effectiveness of a machine. ME = Work Output/Ideal Work Output * 100%. What is Mechanical Efficiency of modern cars, refrigerators, washing machines, LED lights (in %), in other words what percentage of fuel/electrical etc. energy input is used productively in these appliances, and what percentage is wasted?

Question 83725 asked on 2011-08-20 18:40:21

mass of peanut: 1.47 g mass of water: 50 g initial temperature of water: 23 C final temperature of water: 59 C a) Calculate how much energy was absorbed by the water. b) At a submolecular level, where did this energy come from? c) Calculate the quantity of energy produced per gram of fuel (nut) burned. d) Compare this combustion reaction to the reaction that would happen if you were to eat the nut instead of burning it.

Question 84525 asked on 2011-09-26 11:08:21

At work in a food plant that has 600wats of power for our electrical machines. if you get a static shock through your hole body is there a health issue i should be consern about.it really hurts for a while when you get zap.

Question 84814 asked on 2011-10-10 12:07:27

What is the formula for the transverse velocity of a transverse wave?

Question 84815 asked on 2011-10-10 12:09:50

What is the formula for the transverse velocity of a transverse wave?

Question 84889 asked on 2011-10-14 09:44:26

the effect time on the density of the liquid at constant temperature

Question 85833 asked on 2011-12-01 15:20:50

Regarding wind turbines: The blades on these turbines look very heavy. I am wondering if wind alone can start moving these blades from a dead stop (maintenance?) or do they need some kind of assistance to get moving/momentum before the wind is then able to keep the blades moving?

Question 86702 asked on 2012-01-20 11:26:09

Me and my friend and arguing about a science related question. In the scenario where you add salt to water to make it boil faster, is the salt classified as a catalyst? My friend seems to think so, but from what I remember a catalyst aids in a CHEMICAL reaction. Water boiling is a property change rather than a chemical reaction is it not?

Question 87173 asked on 2012-02-07 08:17:05

How matter is created on this universe?