Joule's Experiments

Sadi Carnot was a French engineer who experimented in an attempt to turn heat into mechanical energy. He found that this could only happen when thermal energy flows from a hot to a cold object. He also found that in this, some heat is always lost.

By 1840, scientists knew that heat was not a physical object and that it could be exchanged for mechanical energy. James Prescott Joule substituted the term ‘energy’ for vis viva and said that heat is another form of energy.

Joule’s first experiment supports a connection between heat and potential energy. His first experiment includes two weights, a thermometer and a rotating wheel. As the weight falls the wheel turns and the water heats up. If the mass is raised, the wheel rotates more and the water heat increases. This is due to the loss of gravitational energy from the falling weights and that energy being transferred to the wheel. This energy is kinetic energy and as the wheel turns it is converted into heat.

Joule’s second experiment shows a connection between kinetic energy and heat. This experiment includes two wooden blocks, one stationary and the other in motion, swinging and hitting the stationary block. The moving block has kinetic energy as it swings and loses that energy as it comes in contact with the sitting block. The stationary block has an increase in heat. When the swinging block has an increase in speed, the kinetic energy is increased and therefore, the heat of the unmoving block is also increased in the collision. Joule’s explained that the swinging block’s kinetic energy is passed onto the stationary block in the form of heat.

Later on, other scientists wanted to do more work with energy. They refined technologies and used concepts of work, energy and heat.

Joule’s proved that heat could be created from kinetic energy through his experiments. When the weights dropped or the block swung, heat was produced through the contact or movement. Through his practices, James Joule discovered something that changed science forever.

A website with information about this topic:

http://www.ncert.nic.in/html/learning_basket/energy10class/joule's%20experiment.htm

Information and diagram ideas from Textbook.
Gif made from

Sadi Carnot was a French engineer who experimented in an attempt to turn heat into mechanical energy. He found that this could only happen when thermal energy flows from a hot to a cold object. He also found that in this, some heat is always lost.

By 1840, scientists knew that heat was not a physical object and that it could be exchanged for mechanical energy. James Prescott Joule substituted the term‘energy’ for 'vis viva' and said that heat is another form of energy.

Joule’s first experiment supports a connection between heat and potential energy. His first experiment includes two weights, a thermometer and a rotating wheel. As the weight falls the wheel turns and the water heats up. If the mass is raised, the wheel rotates more and the water heat increases. This is due to the loss of gravitational energy from the falling weights and that energy being transferred to the wheel. This energy is kinetic energy and as the wheel turns it is converted into heat.

Joule’s second experiment shows a connection between kinetic energy and heat. This experiment includes two wooden blocks, one stationary and the other in motion, swinging and hitting the stationary block. The moving block has kinetic energy as it swings and loses that energy as it comes in contact with the sitting block. The stationary block has an increase in heat. When the swinging block has an increase in speed, the kinetic energy is increased and therefore, the heat of the unmoving block is also increased in the collision. Joule’s explained that the swinging block’s kinetic energy is passed onto the stationary block in the form of heat.

Later on, other scientists wanted to do more work with energy. They refined technologies and used concepts of work, energy and heat.

Joule’s proved that heat could be created from kinetic energy through his experiments. When the weights dropped or the block swung, heat was produced through the contact or movement. Through his practices, James Joule discovered something that changed science forever.
A website with information about this topic:

http://www.ncert.nic.in/html/learning_basket/energy10class/joule's%20experiment.htm

Information from textbook.

Gif made from http://www.youtube.com/watch?v=h72njPR_P2Q