If your vehicle has an automatic transmission with overdrive, then at speeds above 45 mph, it should be in overdrive, which reduces engine RPM's to save fuel.
45 mph is the same as 45 mph. How can one of the two be faster?
90seconds
neither
No.
a = (vf - v0)/Δt 10 mph/s = (45 mph - 20 mph)/Δt Δt = 2.5 s
Kinetic Energy
45 mph = 45 miles in an hour = 0.75 miles in a minute = 0.0625 miles in 5 seconds = 0.1 km = 100m.
Overdrive keeps your engine RPMs low when you drive faster than 45 mph Its there for fuel economy If you drive without OD it doesnt hurt anything at all except your gas mileage
80 mph
going 55 mph, its around 45 seconds.
60 miles
At 45mph a car will travel 66 feet per second.