The efficiency of a machine indicates how well its input energy is converted to useful output energy or work. It is a major factor in the usefulness of a machine and is the fraction or percentage of the output divided by the input.
According to the Law of Conservation of Energy, the total output energy or work must equal the total input energy. However, some of the input energy does not contribute to the output work and is lost to such things as friction and heat.
Examples of machine efficiency include a lever, automobile, and perpetual motion machine.
Dark matter may explain <span>unexpected orbital velocities of stars in galaxies.</span>
Answer:
C. The forces are balanced.
Explanation:
Every answer other than C means the object moved.
Answer:
258 Hz or 266 Hz
Explanation:
When two sounds of similar frequency occur at the same time, a phenomenon called "beat" occurs. The beat is an interference patter between the two sounds; the frequency of this beats (called beat frequency) is given by the difference between the frequencies of the two sounds:
where
is the beat frequency
is the frequency of the 1st sound
is the frequency of the 2nd sound
In this problem,
is the beat frequency
is the frequency of the middle C tuning fork
is the frequency of the middle C piano string
Solving for f2, we find two solutions: