Question
Wheel of car is making 5 revolution per second . if the diameter of the wheel is 84cm .find its speed in km/h
Answers
Damon
1 revolution = 2 pi radians
so
5 revs/sec * 2 pi radians/rev = 31.4 rad/s
which is called omega, the angular velocity
r = radius = 42 cm = .42 m
speed at rim = omega r
speed = 31.4 rad/s * .42 m = 13.2 m/s
convert now
13.2 m/s (3600 s/hr)(1 km/1000m) = 47.5 km/hr
so
5 revs/sec * 2 pi radians/rev = 31.4 rad/s
which is called omega, the angular velocity
r = radius = 42 cm = .42 m
speed at rim = omega r
speed = 31.4 rad/s * .42 m = 13.2 m/s
convert now
13.2 m/s (3600 s/hr)(1 km/1000m) = 47.5 km/hr