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3 years ago

13

Which term describes the point when two objects reach the same temperature and there is no longer a transfer of energy through h

eat?

1 answer:

yaroslaw [1]3 years ago

5 0

The term you need to know is equilibrium. Technically it means that heat gained = heat lost. Normally in beginning chemistry classes the evidence for this condition is a stable temperature.

You might be interested in

What is an area of physics that studies motion and its causes?

Solnce55 [7]

It's mechanics
sometimes: Newton's motion

6 0

3 years ago

Two students try to move a heavy box. One pushes with the force of the 80N while the other pulls with a force of 40N in the same

alekssr [168]

Answer:

<em>Good Luck!</em>

Explanation:

Force applied by first student (F1) = 80 N

Force applied by the second student (F2) = 40 N

Displacement (d) = 10 m

Work done by first student (W1) = F1d = 80*10 = 800 J

Work done by second student (W2) = F2d = 40*10 = 400 J

Hence, the work done by the pushing student is 800 J and that by pulling student is

<h2> <u><em>400 J</em></u></h2>

5 0

3 years ago

A closed, rigid tank fitted with a paddle wheel contains 2 kg of air, initially at 300 K. During an interval of 5 minutes, the p

anzhelika [568]

Answer:

The final temperature of the air is $T_2= 605 K$

Explanation:

We can start by doing an energy balance for the closed system

$\Delta KE+\Delta PE+ \Delta U = Q - W$

where

$\Delta KE$ = the change in kinetic energy.

$\Delta PE$ = the change in potential energy.

$\Delta U$ = the total internal energy change in a system.

Q = the heat transferred to the system.

W = the work done by the system.

We know that there are no changes in kinetic or potential energy, so $\Delta KE = 0$ and $\Delta PE=0$

and our energy balance equation is $\Delta U = Q - W$

We also know that the paddle-wheel transfers energy to the air at a rate of 1 kW and the system receives energy by heat transfer at a rate of 0.5 kW, for 5 minutes.

We use this information to calculate the total internal energy change $\Delta U=W+Q$ using the energy balance equation.

We convert the interval of time to seconds $t = 5 \:min = 300\:s$

$\Delta \dot{U}=\dot{W}+ \dot{Q}\\=\Delta U=(W+ Q)\cdot t$

$\Delta U=(1 \:kW+0.5\:kW)\cdot 300\:s\\\Delta U=450 \:kJ$

We can use the change in specific internal energy $\Delta U = m(u_2-u_1)$ to find the final temperature of the air.

We are given that $T_1=300 \:K$ and the air can be describe by ideal gas model, so we can use the ideal gas tables for air to determine the initial specific internal energy $u_1$

$u_1=214.07\:\frac{kJ}{kg}$

Next, we will calculate the final specific internal energy $u_2$

$\Delta U = m(u_2-u_1)\\\frac{\Delta U}{m} =u_2-u_1$

$\frac{\Delta U}{m} =u_2-u_1\\u_2=u_1+\frac{\Delta U}{m}$

$u_2=214.07 \:\frac{kJ}{kg} +\frac{450 \:kJ}{2 \:kg}\\u_2= 439.07 \:\frac{kJ}{kg}$

With the value $u_2=439.07 \:\frac{kJ}{kg}$ and the ideal gas tables for air we make a regression between the values $u = 434.78 \:\frac{kJ}{kg},T=600 \:K$ and $u = 442.42 \:\frac{kJ}{kg}, T=610 \:K$ and we find that the final temperature $T_2$ is 605 K.

3 0

3 years ago

Suppose you are running late in the morning and drying your hair in the kitchen with the hairdryer plugged into the outlet with

lesantik [10]

Answer:

Explanation:

It is given that Hair dryer , Toaster and coffeepot are working simultaneously with power 1200 W , 700 W and 800 W respectively.

So the total power of system is $P_t=1200+700+800=2700\ W$

it is given that they work properly until toast is on.

By switching on the toast, appliance stop working because it may cause the circuit to break to safeguard the circuit.

Circuit breaker frame are used in home to prevent the short circuit

7 0

4 years ago

When growing tomatoes with little sunlight, will using a mirror to reflect the sunlight give the same result as direct sunlight?

telo118 [61]

Answer:

No, it is not d true light

Explanation:

fruits generally plants need a direct sunlight

4 0

4 years ago