Regions in the milky way where density waves have caused gas clouds to crash into each other are called clumps.Clumps are molecular clouds (interstellar clouds) with higher density,where lots of dust and gs cores resides. These clouds are the beginning of stars.
"<em>F = dP/dt. </em> The net force acting on an object is equal to the rate at which its momentum changes."
These days, we break up "the rate at which momentum changes" into its units, and then re-combine them in a slightly different way. So the way WE express and use the 2nd law of motion is
"<em>F = m·A.</em> The net force on an object is equal to the product of the object's mass and its acceleration."
The two statements say exactly the same thing. You can take either one and work out the other one from it, just by working with the units.
Answer:
Some types of electromagnetic waves, like radio waves, microwaves, infrared waves, visible light and ultraviolet waves, can be reflectedSome types of electromagnetic waves, like radio waves, microwaves, infrared waves, visible light and ultraviolet waves, can be reflected
Explanation:
Answer:
The sound travelled 516 meters before bouncing off a cliff.
Explanation:
The sound is an example of mechanical wave, which means that it needs a medium to propagate itself at constant speed. The time needed to hear the echo is equal to twice the height of the canyon divided by the velocity of sound. In addition, the speed of sound through the air at a temperature of 20 ºC is approximately 344 meters per second. Then, the height of the canyon can be derived from the following kinematic formula:
(1)
Where:
- Height, measured in meters.
- Velocity of sound, measured in meters per second.
- Time, measured in seconds.
If we know that 
and 
, then the height of the canyon is:
The sound travelled 516 meters before bouncing off a cliff.
-- The long line and short line close together at the left side
of the diagram represent a single-cell battery.
It's the only one in this diagram.
It's a device that stores chemical energy and delivers it on demand.
-- The zig-zag lines with circles around them represent light bulbs.
There are three of them in this diagram.
They are devices used to produce light by dissipating electrical energy.
-- The zig-zag lines without circles, at the top of the diagram,
represent resistors.
There are two of them in this diagram.
They are devices used to change or control electrical parameters
within a circuit by dissipating electrical energy.
-- The short straight line between two small circles at the bottom
of the diagram represents a switch.
There is only one switch in this circuit.
It's a device used to easily and quickly start or stop the flow of current
past a certain point in a circuit.
In this circuit ...
-- When the switch is closed (as drawn), the light bulb nearest the battery
glows brightest, the light bulb in the middle glows less bright, and the light
bulb on the right side glows dimmest of all.
-- When the switch is open, the light bulb nearest the battery glows, and
neither of the other two light bulbs glows at all.
