acceleration

Question

What is the final speed of a car that accelerates at 20 ft/s2 for 2 seconds if it's initial speed was 33 miles per hour, to 1 decimal place?

Answer 1

It's easiest to convert the initial speed to ft/sec and work from there.

 

initial speed = 33 mi/hr.(5280 ft/1mi).(1 hr/3600s)=33(5280)/(3600)=48.4 ft/s

 

final speed=initial speed +acceleration x time

 

final speed = 48.4+2(20)=88.4 ft/s

 

Convert this back to mi/hr

 

(88.4/5280)(3600)=60.2727... mi/hr = 60.3 mi/hr to one decimal place.