Do not use water on chemical fires such as magnesium, or on electrical fires.
The first law of thermodynamics states that the change in internal energy of a system equals the net heat transfer into the system minus the net work done by the system. In equation form, the first law of thermodynamics is ΔU = Q − W.
Answer:
''
Explanation:
A chemical change results from a chemical reaction, while a physical change is when matter changes forms but not chemical identity. Examples of chemical changes are burning, cooking, rusting, and rotting. Examples of physical changes are boiling, melting, freezing, and shredding. Often, physical changes can be undone, if energy is input.
Answer:
40.34 s
Explanation:
Given,
Velocity (v) = 5.33 m/s
Distance (s) = 215 m
Time (t) = ?
We know that,
Speed (v) = distance (s)/time (t)
⇒ time(t) = distance (s)/speed (v)
= 215/5.33 = 40.34 sec
∴ time(t) = 40.34 sec.