What Determines the Change in Thermal Energy of a Block Pulled Across a Surface?

In summary, the change in thermal energy of a block of mass M being pulled at constant speed with force F a distance d across a surface can be determined using the energy principle. If the block is traveling at constant speed, then the change in thermal energy would be 0 (b) as there is no change in kinetic energy and no friction force present. However, if there is a presence of friction, then there would be a positive change in thermal energy (c) due to the formation of heat.
  • #1
Westin
87
0

Homework Statement



A block of mass M is pulled at constant speed with force F a distance d across a surface. Using the energy principle, what can you say about the change in thermal energy of the block?

a) [PLAIN]https://s3.lite.msu.edu/adm/jsMath/fonts/cmr10/alpha/144/char01.pngEtherm[PLAIN]https://s3.lite.msu.edu/adm/jsMath/fonts/cmmi10/alpha/144/char3C.png0 [/B]
b) [PLAIN]https://s3.lite.msu.edu/adm/jsMath/fonts/cmr10/alpha/144/char01.pngEtherm=0
c) [PLAIN]https://s3.lite.msu.edu/adm/jsMath/fonts/cmr10/alpha/144/char01.pngEtherm[PLAIN]https://s3.lite.msu.edu/adm/jsMath/fonts/cmmi10/alpha/144/char3E.png0[/B]

Homework Equations

The Attempt at a Solution



I believe the change in thermal energy is 0 (b) because it is being pulled at a constant speed so nothing is actually changing. Is my logic correct to say it is b?

I only have one attempt left
 
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  • #2
Of it's traveling at constant speed, then what can you say about the presence or absence of a friction force?
 
  • #3
Chestermiller said:
Of it's traveling at constant speed, then what can you say about the presence or absence of a friction force?
If you are at constant speed, that means that the acceleration you are providing is equal to the deceleration from the friction. If those are not equal then the speed is increasing or decreasing. KE isn t changing. However, heat it formed so there would be a positive change of thermal energy? So C?
 
  • #4
Westin said:
If you are at constant speed, that means that the acceleration you are providing is equal to the deceleration from the friction. If those are not equal then the speed is increasing or decreasing. KE isn t changing. However, heat it formed so there would be a positive change of thermal energy? So C?
Westin said:
If you are at constant speed, that means that the acceleration you are providing is equal to the deceleration from the friction. If those are not equal then the speed is increasing or decreasing. KE isn t changing. However, heat it formed so there would be a positive change of thermal energy? So C?
Correct.
 

Related to What Determines the Change in Thermal Energy of a Block Pulled Across a Surface?

1. What is thermal energy?

Thermal energy is a form of energy that is associated with the movement of particles within a substance. It is the sum of the kinetic energy of all the particles in a system.

2. How does thermal energy change?

Thermal energy can change in several ways, including through heating or cooling, changes in pressure, and changes in the system's volume. These changes can cause the particles in a substance to either speed up or slow down, resulting in a change in thermal energy.

3. What is the relationship between temperature and thermal energy?

Temperature and thermal energy are closely related, but they are not the same thing. Temperature is a measure of the average kinetic energy of particles in a substance, while thermal energy is the total kinetic energy of all the particles in a system.

4. How is thermal energy measured?

Thermal energy is typically measured in joules (J) or calories (cal). Scientists use special instruments, such as calorimeters, to measure the amount of thermal energy in a substance.

5. How does thermal energy affect matter?

Thermal energy can cause matter to change state (e.g. from solid to liquid), expand or contract, and undergo chemical reactions. It also plays a crucial role in the movement of matter and the transfer of heat between objects.

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