# Temperature and Internal Energy/Time to heat water

• juanita
In summary, the conversation discusses the comparison of temperature (T) and internal energy (U) of water scooped from a swimming pool and placed in a cup. Option a) states that the temperature of the pool (Tpool) is lower than the cup (Tcup), but the internal energy is the same. Option b) states that the temperature of the pool and cup are equal, but the internal energy of the pool (Upool) is lower than the cup (Ucup). Option c) states that both the temperature and internal energy of the pool and cup are equal, while option d) states that the temperature of the pool is higher than the cup, but the internal energy is the same.As for the second problem,

#### juanita

A cup of water is scooped up from a swimming pool of water. Compare the temperature T and the internal energy U of the water, in both the cup and the swimming pool.
a) Tpool is less than Tcup, and the U is the same.
b) Tpool is equal to Tcup, and Upool is less than Ucup.
c) Tpool is equal to Tcup, and Upool is greater than Ucup.
d) Tpool is greater than Tcup, and the U is the same.

A 5 kW heater is used to heat water. How long will it take to heat 20 kg of water from 20 degrees celsius to 100 degrees celsius?
a) 32 minutes
b) 2 minutes
c) 12 minutes
d) 22 minutes

any help would be appreciated, thanks!

Welcome to PF

What are your thoughts on how to solve the problems? What equations (from your textbook or class lecture) do you think would apply here?

## 1. What is the difference between temperature and internal energy?

Temperature is a measure of the average kinetic energy of particles in a substance, while internal energy is the total energy of all the particles in a substance. Temperature is a macroscopic property, while internal energy is a microscopic property.

## 2. How is the temperature of a substance related to its internal energy?

The temperature of a substance is directly proportional to its internal energy. This means that as the temperature increases, the internal energy also increases and vice versa.

## 3. How long does it take to heat water to a certain temperature?

The time it takes to heat water to a certain temperature depends on the initial temperature of the water, the amount of water, and the rate of heat transfer. However, as a general rule, it takes about 4.186 joules of energy to raise the temperature of 1 gram of water by 1 degree Celsius.

## 4. What factors affect the time it takes to heat water?

The time it takes to heat water is affected by the initial temperature of the water, the volume of water, the heat source, and the efficiency of the heating process. Other factors such as atmospheric pressure and altitude can also have an impact.

## 5. Can the internal energy of a substance change without a change in temperature?

Yes, the internal energy of a substance can change without a change in temperature. This can occur through physical changes such as phase transitions (e.g. melting or boiling) or chemical reactions. In these cases, the energy is used to break intermolecular forces rather than increase the temperature.