Tag Archives: science

Physics Specific Heat Problems

physics specific heat problems
Solving specific heat—physics problem. HELP!?

Please help me solve this problem. I’ve been working on this for like 3 hours and have not yet come up with an answer. If you get an answer, can you please show your work?

A hot, just-minted copper coin is placed in
116 g of water to cool. The water temperature
changes by 8.00 °C and the temperature of the
coin changes by 87.3 °C.

What is the mass of the coin? Disregard
any energy transfer to the water’s surround-
ings and assume the specific heat of copper
is 387 J/kg°C. The specific heat of water is
4186 J/kg°C.

Answer in units of g.

Thanks so much.

OK … here we go:

The energy absorbed by the water is:

E = 4184J/(kg*C)*8C*0.160kg = 495.36J

For the copper, we want to know the mass so let’s multiply its specific heat by what we know and see what happens. Note: we must use the inverse of the specific heat to get the units right and get an answer in grams. Lets try:

(kg*C/387J)*(495.36J/87.3C) = 0.014662kg or 14.662g

Lets check it just to make sure.

E = 387J/(kg*C)*87.3C*0.014662kg = 495.36J

Both the copper and the water exchanged the same number of joules!

The answer is 14.662 grams of copper.

Best,
Dave

Physics: Thermodynamic processes (1)

Specific Heat Problems Chemistry

specific heat problems chemistry
AP chemistry specific heat problem?

a coffee cup calorimeter contains 50 g of water at 60.51 degrees celcius. a 12.4g piece of graphite at 24.21 degrees celcius is placed in the calorimeter. the final temperature of the water and the carbon is 59.02 degrees celcius. calculate the specific heat of carbon. the specific heat of water is 4.18 j/g*C

thank you

59.02C – 24.21C = 34.81degC temperature change for graphite

60.51C – 59.02C = 1.49degC temperature change for water

(50gH2O)(1.49degC)(4.18J/gH2O) = 311.41 J heat lost by water and gained by graphite (G)

(311.41J)/(12.4gG)(34.81degC) = 0.7214 J/g-degC

Specific Heat Capacity Sample Problem 1

Chemistry Specific Heat Problems

chemistry specific heat problems
chemistry specific heat?

im going over some chemistry problems before school starts back, but i dont understand this specific heat problem…need help.

a sample of metal with a mass 250g is heated to 130 degrees C and dropped into 425g of water at 26 degrees C. The final temperature of the water is 38.4 degress C. What is the specific heat capacity of the metal if 1.2 x 10 ^3 J are lost to the environment?

PLEASE AND THANK YOU!

q (water) = 425 g x 4.18J x ( 38.4 – 26) = 2.20 x 10^4 J
2.20 x 10^4 – 1.2 x10^3 = 2.08 x 10^4
q ( metal ) = – 2.08 x 10^4 J
q ( metal) = 250 g x specific heat x ( 38.4- 130 ) =
– 2.08 x 10^4
specific heat = 0.908 J / g °C

Specific Heat

Heat Projectiles

heat projectiles
Physics Roller Coaster Loop, projectile motion, and heat help!?

Does a roller coaster loop demonstrate circular motion? If so, why and what is the equation? What is the equation for projectile motion? What is the equation for heat, is it something like average temperature = (g)(c)(degrees)?

Thanks!!

There isn’t one single formula for circular motion
or for projectile motion
or for heat

Physics would take about 10 minutes to learn if there were.

US Finances Pakistan, Pakistan Supplys and Finances Taliban, Taliban Get Heat Seeking Missiles

Pool Chemicals Bulk

pool chemicals bulk
How much does bulk water cost? and other pool questions?

I am looking to lease a home with an in ground pool and I would like some advice from pool owners. How much per gallon did you pay for your bulk water, I know it fluctuates depending on region, I’m in the midwest, but Id like an idea of what others pay. Also do you hire a company to do the weekly maintenance or do you do the chemicals yourself, which do you find to be more cost effective? Any other advice for keeping pool maintenance costs down are appreciated.

In Southern Arizona, bulk water delivery is charged at a penny a gallon and $95 per hour for the water truck. The last pool I designed and had to be filled that way ended up running around $850 for 13,000 gallons.

It is always cheaper to do it yourself, but you have to be honest with yourself as to whether or not you feel like you can keep on top of the maintenance. If you ‘let the pool go’ and let the chemistry get out of whack, you can damage the equipment or the interior surface, which cost a heck of a lot more than pool service.

Again, using southern AZ as a guide, you can expect to pay from $50-$125 per month on a service, which includes chemicals. The variance in price is because some services are water chemistry only, and do not perform other maintenance services like cleaning filters, salt cels (if you have one) and so on.

Maintaining a pool is a lot like maintaining a car – you can skip oil changes and not check the air pressure in the tires and save a little, or you can buy tires more often and replace the engine at 60,000 miles.

Specific Heat Problems Physics

specific heat problems physics
physics specific heat question?

just a little question about physics.
in a physics specific heat problem, why don’t you need to convert Kelvins into Celsius degrees?
For example, Find the amount of heat required to raise the temperature of 460 g of silver from 273 K to 300 K.
The equation is Q=mct with t being the change in temperature. The heat required is 234 J/kgC.
The book says that the change in temperature is 27 K and that’s the same as 27 Celsius degrees. I don’t understand this. Shouldn’t you change the 27 K into Celsius degrees by subtracting it from 273?

Although the Celsius and Kelvins scale differ in “where 0 is”,a degree in each scale has the same “size” . So when you only need differences in temperature, it does not matter numerically if you use Kelvin or Celsius.
In formula: K1 = C1 + 273, K2 = C2 + 273 , so
K2 – K1 = C2 + 273 – ( C1 + 273) = C2 – C1

Physics #2 – Density & Specific Heat.wmv