If by LFM you mean linear feet per minute, then the calculation is quite simple:
53 ft/min x 1 mile/5280 ft x 60 min/hour = 0.60 mi/hour
this is slower than normal walking speed, which is about 3 mi/hr
3 mi/hr is about 264 feet/minute
53 mph
lfm in heatsink is "linear feet per minute" which is a unit for measuring airflow. Heatsinks are rated to work differently at different airflow which are measured in lfm or sometimes m/s (meters per sec)
53 x 5280 = 279,840 ft in one hour
53 km/h = 32.93 mph
77.73 feet every second.
At an average 60 mph: 12 hours, 53 minutes
53 and a half minutes
The GZ20 can go 53 mph
17/53 = 0.3208hour (rounded) = 19minutes 14.7seconds (rounded)
53 mph
53 metres/ 175 feet
The top speed of The Racer is 53 mph.