Fax Initials Formula with airSlate SignNow

Fax initials formula

I don't have any videos yet about heat and Q equals MC delta T so here we are how much heat is released when 240 grams of iron cools from 90 to 25 to figure out the amount of heat that is transferred in the process you can use the formula Q equals mass times specific heat capacity times the change in temperature I hope it's obvious that M is for mass here so in this case it's just 240 grams C stands for specific heat capacity it's usually going to be given to you if they tell you what the substance is iron has a specific heat capacity of 0.45 to joules for every gram heated up by one degree Celsius that's joules per gram degrees Celsius now delta T is a little tougher delta T is equal to the final temperature minus the initial temperature which in this case is 25 degrees Celsius and we're going to subtract 90 degrees Celsius that gives me negative 65 degrees Celsius and delta T is negative because the temperature went down from 90 to 25 so I'm going to plug negative 65 degrees Celsius in here if you're given temperatures in Kelvin you can use those here as well for Delta T degrees Celsius and Kelvin are the same unit that's not true if it's regular temperature but for the change in temperature it happens to be true now my son just disappeared 240 grams times 0.45 to joules per gram degree Celsius times negative 65 gives me a value of negative seven zero five 1.2 my grass cancels with the unit of grams and my degree Celsius cancels with the unit of degree Celsius that's why this unit for specific heat capacity works and I'm left with joules now I can convert that to kilojoules by dividing by a thousand I'm gonna take a couple digits off that as well so I'm releasing that's what the negative is for seven point zero five kilojoules of heat when this process occurs it's a pretty easy formula the more tough although also easy questions that you're gonna be asked are solving for either M or C or delta T for example what mass of water can be heated from 20 to 100 by 650 kilojoules of energy the first thing I want to point out is that 650 kilojoules is 650,000 joules I'm just multiplying by a thousand to get that value to solve for mass in the equation Q equals MC delta T you divide both sides by C and delta T so I've derived this formula for mass as long as I'm given am at an amount of energy now we are heating water and it's absorbing 650,000 joules so I'm gonna plug that in with a positive sign the specific heat capacity of water is 4.184 joules per gram degree Celsius and my temperature is going up by 80 degrees so that's a delta T of positive 80 degrees if you want to use the final minus initial formula its final minus initial 100 minus 20 is 80 cool so we can do this on the calculator as well 650,000 divided by now when you're typing listen to the calculator you need to put brackets around the whole denominator you have to say it's divided by this whole product instead of just this divided by this times this the calculator will do this division before it does this multiplication if you don't add these brackets in there so can you see what I'm typing here it's open bracket 4.184 times 80 closed bracket the answer here is one nine four one 9 now my Jules cancels with my jewels my degrees Celsius cancels with my degrees Celsius and because I'm dividing by per grams this ends up being regular grams now I can convert that to kilograms if I divide by a thousand can you tell you'll be doing that a lot in these types of questions yes you can apparently adding 650 kilojoules of heat can heat up 1.94 kilograms of water by eighty degrees Celsius strange but true and the last thing you might be asked to solve for well you could be asked to solve for Delta T but I have another formula for that or I have another video for that I should say is that if we're adding 968 joules of energy to something and it weighs 50 grams and we only want to heat it by 10 degrees Celsius what's the specific heat capacity well we can solve for C in Q equals MC delta T by dividing Q by M and delta T so the amount of energy here is 968 joules the mass was 50 grams and the delta T is from 30 to 40 so that is up positive 10 degrees Celsius now let's do that on the calculator I get 968 divided by open bracket 50 times 10 that gives me 1 point 9 3 6 and my unit's here nothing cancels so I have joules over grams and degrees Celsius now if you're given a table of specific heat capacities like water being 4.184 and iron being whatever I said it was 0.45 - you can look through for something that's about 1.9 and then you might even be able to identify what the substance is now I don't have a table with me and I don't have any idea of what chemical in the world has this heat capacity I think it's a little close to steam but I have nothing to prove that so I can't make any more hypotheses from this but the point is we calculated the specific heat capacity using Q equals MC delta T and we just rearranged the formula just like we solved for mass and just like you can solve for Q pretty easy don't mess it up practice makes perfect best of luck