Thermo Definition and 267 Threads

hi guys, i have the following question to answer: a 40g copper calorimeter contains 200g of water at 20 degrees celsius, it asks how much stam must be condensed in order to achieve a final temperature of 50 degrees celsius. I was just wondering what formula to use?, and do i need to know the...

hi guys, i have a thermodynamics question. a 2.50 kg iron object is initially at 650 degrees celsius and dropped into a bucket containing 20kg of water at 25 degrees celsius, what is the final temperature? As always it just a matter of applying the formula, but i don't seem to be applying...

Hello. I have a thermodynamics exam tomorrow. This is a past exam question and I'm not doing very well with it. If anyone has any ideas please help! A charge enters a spark ignition engine at 330K and 1 bar, and is isentropically compressed through a ratio of 7:1. Estimate the temp and...

Q. The air in a 6m x 5m x 4m hospital room is to be completed replaced by conditioned air every 20 min. If the average air velocity in the circular air duct leading to the room is not to exceed 5 m/s, determine the minimum diameter of the duct. We can figure out the volume of the room...

Having problems with a thermo. cycle! OK, so in the problem A->B is isobaric, B->C is adiabatic, C->D is isothermal, D->A is isochoric. Pa = 2atm, Va = 2 m^3, n = 1mole, Vb = 1/2Va, Pa = 2Pd (That is all the information that is given.) I always end up with the temperatures of B and C...

Hello, If anybody could answer this question for me that would be great. I have been wondering about it all morning. In the Diesel cycle for heat engines, on the second stage of operation, the Volume increases while pressure stays the same. I understand how this can be accomplished by raising...

Hello, If anybody could answer this question for me that would be great. I have been wondering about it all morning. In the Diesel cycle for heat engines, on the second stage of operation, the Volume increases while pressure stays the same. I understand how this can be accomplished by raising...

Hello all, I am a little confused on this problem and want to be clear on it. Given: Water is boiled at 1 atm pressure in a 20-cm i.d. pan. Water level in pan drops by 10cm in 30 min, determine the rate of heat transfer to the pan. Now correct me if I'm wrong but water boils at 100...

A startled armadillo leaps upwards so that it rises to .56 m in a time .21 s. Note: I use a web-submitting thing for my answers. So it tells me what is right and wrong. A: What was the armadillo's initial speed when it left the ground? 3.70 m/s - this part is correct. B: What is its...

How would you guys explain "qualitatively" the theorem of maximum work based on this diagram. (that is when a process is reversible and no entropy change in the universe) I don't really know what the graph means. Let's say it's an ideal gas, (S=LnU+...). The diagram divides the plane in two...

For a device operating at steady state, is the change in entropy (S2-S1) equal to 0? If it is equal to 0, then why doesn't the s2-s1=s(degree)(T2)-s(degree)(T1) - R ln (p2/p1) equation yield 0? I'm confused on this point... Any help greatly appreciated!

Need urgent help with thermo problems... Here are my problems: 1) A rigid tank contains 5 lb of a two-phase liquid vapor mixture of water, initially at 260 F with a quality of .6 Heat transfer to the contents of the tank occurs until the temperature is 320 F. Determine the initial mass of...

Here's my problem: Measured data for pressure versus volume during the expansion of gases within the cylinder of an internal combustion engine are given in the table below. Data Point p (bar) V (cubic cm) 1 15...

An ideal gas initially at Pi, Vi, and Ti is taken through a cycle as in Figure P20.38 (n = 2.6). Figure P20.38 (see attachment) (a) Find the net work done on the gas per cycle. PiVi (b) What is the net energy added by heat to the system per cycle? PiVi (c) Obtain a numerical value...

A single 50g ice cube is dropped into a thermally insulated container holding 200g of water. The water is initially at 25oC and the ice is initially at -15oC. ********** a) What is the final temperature of the system after is has come to thermal equilibrium ? b) Now let's drop a second...

An aluminum calorimeter of mass 100 g contains 250 g of water. The calorimeter and water are in thermal equilibrium at 12.0°C. Two metallic blocks are placed into the water. One is a 40.0 g piece of copper at 80.0°C; the other block has a mass of 13.0 g and is originally at a temperature of...

A 1.0 g lead bullet at 33°C is fired at a speed of 250 m/s into a large block of ice at 0°C, in which it becomes embedded. What quantity of ice melts? Heres what I have: From ΔQ = mcΔT, mA = dQ/[c(dT)] And from ΔQA = -ΔQB ... Further cogitations are in...