Answer:
revolutions per minute for 16 inches is 946 / minute
revolutions per minute for 14 inches is 1081 / minute
Step-by-step explanation:
Given data
radius = 16 inch
speed = 90 mph  = 90/60 = 1.5 miles/minute = 1.5 × 5280 feet /12 inches = 95040 inches /minute
radius 2 = 14 inches
to find out
revolutions per minute
solution
first we calculate the circumference of the wheel i.e. 2×[tex]\pi[/tex]×radius
circumference = 2×[tex]\pi[/tex]×16
circumference = 32[tex]\pi[/tex]
we know that revolution is speed / circumference
revolution = 95040/32[tex]\pi[/tex]
revolution = 945.38 / minute
we have given radius 14 inches than revolution will be i.e.
revolution = speed / circumference
circumference = 2×[tex]\pi[/tex]×14
circumference = 28[tex]\pi[/tex]
revolution = Â 95040/ 28[tex]\pi[/tex]
revolution = 1080.43 / minute
