Question

assignment 1b - temperature and kinetic energy
directions 1 - 12: determine whether the bolded term makes each statement true or false. if the statement is true, write true in the blank. if the statement is false, write false the blank

1. particles that make up matter are in constant motion.
2. the faster particles move the less kinetic energy they have.
3. temperature is the measure of the average kinetic energy of the particles in an object.
4. when temperature increases, the average kinetic energy of the particles decreases.
5. the thermal energy of an object is the total energy of the particles in a material.
6. a thermometer is used to measure the specific heat of a material.
7. thermal energy flows from a higher temperature to a lower temperature.
8. heat is measured in newtons.
9. the same amount of different materials need the same amount of heat to have the same change in temperature.
10. the amount of energy it takes to raise the temperature of 1 kg of a material 1 kelvin is the specific heat of the material.
11. water has a relatively low specific heat.
12. materials with a high specific heat can absorb a lot of energy and show little change in temperature.

Explanation:

1. According to the kinetic - molecular theory of matter, particles that make up matter are in constant motion.
2. Kinetic energy formula is \(KE=\frac{1}{2}mv^{2}\), so the faster particles move (higher \(v\)), the more kinetic energy they have.
3. Temperature is defined as the measure of the average kinetic energy of the particles in an object.
4. Since temperature is related to average kinetic energy (\(T\propto\overline{KE}\)), when temperature increases, the average kinetic energy of the particles increases.
5. Thermal energy is the total kinetic and potential energy of the particles in a material.
6. A thermometer is used to measure temperature, not specific heat. Specific heat is calculated using \(Q = mc\Delta T\).
7. Thermal energy (heat) flows from a region of higher temperature to a region of lower temperature according to the second law of thermodynamics.
8. Heat is measured in joules. Newtons are the unit of force.
9. Different materials have different specific heats (\(c\)). Using \(Q = mc\Delta T\), for the same \(m\) and \(\Delta T\), different \(c\) means different \(Q\).
10. The specific heat \(c\) is defined as the amount of energy it takes to raise the temperature of \(1\space kg\) of a material \(1\space K\) (or \(1^{\circ}C\)) (\(Q=mc\Delta T\), when \(m = 1\space kg\) and \(\Delta T=1\space K\), \(Q = c\)).
11. Water has a relatively high specific heat (\(c_{water}=4200\space J/(kg\cdot K)\)).
12. From \(Q = mc\Delta T\), for a given \(Q\) and \(m\), a higher \(c\) means a smaller \(\Delta T\).

Answer:

1. true
2. false
3. true
4. false
5. false
6. false
7. true
8. false
9. false
10. true
11. false
12. true