the reddish brown gas is NOX, now you just think the substance reacted with iron is nitrate salt of some metal X......hope you know the Metal X ,,,
<u>Answer</u>:
Final velocity: 1200 m/s
<u>Explanation</u>:
Formula: 
<u>Where</u>:
a = average acceleration
v = final velocity
vo = starting velocity
t = elapsed time
<em>Here the final velocity is unknown which we have to find. The initial is 0 m/s</em>
<em>as it was at rest. The time taken: 150 seconds. Acceleration given 8.0 m/s²</em>
using the formula:


m/s
Answer:
physical
Explanation:
no chemical reaction is happening