the wheel of a car has diameter 56cm. (1) how much times does it rotate when the car has travelled 11km. (2) if the wheel has rotated 25000 times when the car has travelled fr 45 minutes, calculate speed in km/hr

 radius = 56/2 cm = 28 cm

circumference of wheel = 2 pie r

                                           = 2 x 22/7 x 28

                                           = 176 cm

distance = circumference x no. of revolution.

1100000 = 176 x no. of revolution

no. of revolution = 6250

2) no. of revolution = 25000

 time = 45 minutes = 45/60 hr

distance = speed x time

no. of revolution x circumference = speed x time

25000 x .00176 x 60/45 = speed

2640/45 = speed