Question

PLS HELP!
Miguel won a bicycle race. The wheel on Miguel's bike had a 67-cm diameter. His average linear speed during the 19th stage of the race was 48.461 km/hr. What was the angular speed of the wheel in revolutions per hour?

Answer 1

Each revolution meant a distance of pi D = 2.10 m.

revolutions per hour = velocity (per hour)/distance per revolution.

Answer 2

C=67pi right? is that how u start?

Answer 3

How far does he go when the wheel goes around once?

Answer 4

67 cm?

Answer 5

In other words, what is the circumference of the wheel?

Answer 6

67pi cm

Answer 7

That would be 210.5 cm.

Answer 8

can u explain how?

Answer 9

never mind ok then what?

Answer 10

67 times 3.14159=67pi

Answer 11

sorry i got that

Answer 12

48.461 km = 48461 m = 4846100 cm

Answer 13

ok.. but so youd set up a ratio to convert it into cm?

Answer 14

can u show me how you would set up the ratios one by one, since this is like dimensional analysis?

Answer 15

48.461 km x 1000m/1km x 100 cm/1 m =

Answer 16

ok so units would cancel

Answer 17

but we're not done right?

Answer 18

you get it?

Answer 19

And 4846100 cm/ 1 hour x 1 rev/210.5 cm = 23022 revolutions/hour

Answer 20

And that is the angular speed in revolutions per hour.

Answer 21

thank you so much.

Answer 22

yw