Answer:
The total mechanical energy of a pendulum is conserved neglecting the friction.
Explanation:
- When a simple pendulum swings back and forth, it has some energy associated with its motion.
- The total energy of a simple pendulum in harmonic motion at any instant of time is equal to the sum of the potential and kinetic energy.
- The potential energy of the simple pendulum is given by P.E = mgh
- The kinetic energy of the simple pendulum is given by, K.E = 1/2mv²
- When the pendulum swings to one end, its velocity equals zero temporarily where the potential energy becomes maximum.
- When the pendulum reaches the vertical line, its velocity and kinetic energy become maximum.
- Hence, the total mechanical energy of a pendulum as it swings back and forth is conserved neglecting the resistance.
An infant galaxy that is studied through the use of radio waves is called QUASAR.
Quasar are astronomical object, which have very high luminosity and they are found in the centers of some galaxies. Scientists believed that quasar are centers of distant galaxies. Radio waves is used to study quasar because they emit a huge amount of radio waves.
Answer:
45 W
Explanation:
First of all, we need to find the work done by the person to lift the bag. The work done is given by
where
F = 75.0 N is the force applied
d = 1.50 m is the displacement of the bag
Substituting numbers into the formula,
Now we can find the power used, which is given by
where
t = 2.50 s is the time taken
Again, using W=112.5 J, we find
