Sound energy is produced when an object vibrates so an example would be a telephone ringing or someone playing a bass guitar
1.55 × 10^3 would be the scientific notation
Answer:
The two main categories of boat hull designs are;
- Displacement Hull
- Planning Hull
Explanation:
<u>Displacement Hull</u>
This type of boat hull is designed to displace certain amount of water as it moves. This displacement enable it to insert its body into the water and continue to displace water from its was as it moves. The weight of water displaced is usually equal to the weight of the boat.
Displacement Hull and Speed
Because of the need to displace water from its path to enable it insert itself into the water body for movement, the speed is usually slow compared to planning hull boats.
Displacement Hull Types:
- Round bottomed hull boat: Their hulls are made to have a round bottom in order to displace water and move smoothly through it. It can move quietly at low speed. How ever, they require complex stabilizer to control them from banking.
- Multi hull boat: This type of hull design has a large and long beam that make it to be very stable on the water body. They usually have ends pointed downwards for proper insertion and displacement. However, they don't turn easily on small space due to their large beam requirement.
<u>Planning Hull</u>
Planning hull boats are designed to slide very fasly on the water surface with very little or no insertion. They require boat engines that operates at a very high revolution per minute(rpm).
When at rest, that is at zero speed, they behave like displacement hull boats but only a small amount of water is displaced a they are usually lighter.
Planning hull boats can operate in three modes:
- Displacement mode: This mode is used when planning hull boats move at extremely slow speed. At this mode, they push water side ways as they move.
- Planning mode: This mode is activated as the speed of the boat increases to enable it glide on the surface of the water.
- Plowing mode: This mode is reach when the bow of the boat is trusted up and suspended as it slides through the surface of the water at a very high speed
Planning Hull and Speed
The speed of planning hull boats is very high when compared to displacement hull boats. This high speed of operation is powered by high rpm engines to enable it slide on the surface of the water.
Planning Hull Types/Merit and Demerit
- Flat Bottom Hull: Their hull is flat bottom shaped and has a draft that supports its suspension on water on a stable manner. Suitable for stable water. However, it moves haphazardly on shaky water.
- Deep Vee Hull: It has a V-shape hull that points towards the water body. Its V-shape makes it glide through rough water surfaces more smoothly than the flat bottom hull. However, it requires more power to operate and easily banks during sharp turning.
Free fall means rapid fall or a downward motion due to gravity. Sentence example: When Joe was accidentally bumped by Sarah, he was sent towards a free fall down the escalator, leading to a serious injury on his arm and two legs.
Electromagnetic waves about the size of a golf ball are used for
microwave radio communication and radar every day.
Electromagnetic waves that are about 4-1/2 inches long are used
in the microwave oven to heat leftover meatloaf and make popcorn .
Electromagnetic waves that are 10 times the size of an atom
are hard hard X-rays.
Electromagnetic waves that are the size of Earth's diameter
are used for ELF communications, including standard time
signals, and submarine communication.
Mechanical waves that are the same order of magnitude as
the Earth are seismic (earthquake) waves.
Gamma rays are electromagnetic waves with wavelengths in the
neighborhood of the same size as the atomic nucleus. To get
some idea of their frequency, just contemplate how long it would
take light ... (which can get to the moon in a couple of seconds) ...
to move from one side of an atomic nucleus to the other side.