If I did my math correctly I believe your answer will be C. :)
Answer: C. Engine life decreases steady with time.
Step-by-step explanation:
E=mc^2 if m=3 and c=6
e=3(6^2)
e=3(36)
e=108
The explorer's running velocity will be 1/3 the velocity of the train, 45/3 = 15.
From those issue statement, the train will a chance to be at the begin of the span The point when those voyagers have run 1/3 of the period of the span. In they run of the much end of the bridge, they will bring run 1/3 of the length of the span when those prepare achieves the close to wind. Beginning starting with those 1/3 point, they will make toward those 2/3 perspective At those prepare achieves those span. The prepare will travel the full period of the span in the the long haul it takes those voyagers to run those remaining 1/3. Accordingly the train must travel toward three times the running speed of the voyager. Train = 45 mph, voyagers = 15 mph.
The speed of P&D = 15 mph