college physical science
posted by ann .
What is the force exerted by a train travelling from rest to 120 mph in 15 min? The train weighs 200,000 lbs.

Convert units 120mph equals 120*5280*(1/60)= 10560 ft/min
a=ft/min/min
a=10560/15= 704ft/min^2
F=ma
F=704*200000=140800000 lb*ft/min^2