Answer:
Burning coal and boiling water are both chemical changes. Burning coal is a chemical change, and boiling water is a physical change. Burning coal is a physical change, and boiling water is a chemical change.
Explanation:
Velocity is a vector quantity. Therefore, while specifying the magnitude of velocity, we also need to mention in what direction its vector *point* in space.
Here, velocity of plane is "500 m/s towards west"
"per second" is exactly the definition of "Hertz".
50 per second is 50 Hz. (B)
The first one is D hunted with stone-tipped spears
The second one is A
Hope this helps
Answer:
Mercury is the closest planet to the sun and ice exist at the down part of the poles craters this might seem hilarious but it is actually true.