Answer:
People are exposed to sources of radiation in all aspects of everyday life. Radioactive sources can be very useful but need handling carefully to ensure safety.
Explanation:
"Frequency" means how often something happens. When you say how many times it happens every SECOND, you can call the number Hertz, or Hz.
In the graph, there are 10 vibrations in 10 seconds, 20 of them in 20 seconds, and 30 in 30 seconds. This should pretty much shout at you "THERE'S ONE VIBRATION EVERY SECOND !". When you realize that, you can say the frequency of the vibration is 1 Hz.
The graph tells us nothing about the speed of the waves. I suspect there's another picture to the question that you didn't include. If the other part shows the wavelength, then we could figure out the speed. But with just what you're showing us, we can't.
C.Earth is the largest and most dense of the terrestrial planets
<span>"Time is like wax, dripping from a candle flame. In the moment, it is molten and falling, with the capability to transform into any shape. Then the moment passes, and the wax hits the table top and solidifies into the shape it will always be. It becomes the past, a solid single record of what happened, still holding in its wild curves and contours the potential of every shape it could have held."</span>
Answer: An jack makes changing a tire easier because it lifts up the car to get the tire off of the ground.
Explanation:
