Hydrogen .When acids touches all metal hydrogen gas is emitted .Strong acids is one that can produce a high concentration of hydrogen ions.Hope this helped!
Answer:
30N in the direction the 45N acts.
Explanation:
Fnet = F1 + F2 (the vector sum of the forces)
Assigning a positive direction to the 45N force and a negative direction to the 15N force gives:
Fnet = 45 - 15
Fnet = 30N
Since the answer is positive, it is in the direction the 45N force acts.
there are situations where the motion is inferred through indirect evidences. For example, we infer the motion of air by observing the movement of dust and the movement of leaves and branches of trees. What causes the phenomena of sunrise, sunset and changing of seasons? Is it due to the motion of the earth? If it is true, why don’t we directly perceive the motion of the earth?
<span>An object may appear to be moving for one person and stationary for some other. For the passengers in a moving bus, the roadside trees appear to be moving backwards. A person standing on the road–side perceives the bus along with the passengers as moving. However, a passenger inside the bus sees his fellow passengers to be at rest</span>
Earth's land and ocean surface to the atmosphere.