Answer:
lower
Explanation:
The lower the value of the coefficient of friction, the lower the resistance to sliding.
The coefficient of friction is the ratio of the frictional force and the normal force pressing two surfaces in contact together.
U = 
U is the coefficient of friction
F is the frictional force
N is the normal force
We see that coefficient of friction is directly proportional to frictional force.
Answer: Looked it up but
Explanation:
When the skater lands on the track, the vertical component of his kinetic energy is converted to thermal energy. You can do experiments where there is no loss to thermal energy (only PE and KE conversions) by turning friction off and by making sure the skater doesn't leave the track.
A pendulum is an object hung from a fixed point that swings back and forth under the action of gravity. In the example of the playground swing, the swing is supported by chains that are attached to fixed points at the top of the swing set. When the swing is raised and released, it will move freely back and forth due to the force of gravity on it. The swing continues moving back and forth without any extra outside help until friction (between the air and the swing and between the chains and the attachment points) slows it down and eventually stops it.
If you want to change the thermos into an open energy system, you have to remove the lid. Once the lid is removed, the energy is no longer contained inside the thermos bottle. From the bottle, the energy dissipates to the environment.
