The ratio of pedal turns to rear-wheel turns in first gear is 7 to 11. How many times in first gear dose the rear-wheel turn if pedals turn 140 times
140/x = 7/11
Suppose a rider travelled 6.4 km in 24 minutes using a gear ratio of 1.5. What would be the circumference of the rear wheel in mm?
6.4 km in 24 minutes = ______ mm in 1 minute
This is the same as _________ mm in 1 minute
This is the same as ________ mm in 1 second
If the gear ratio was 1, the bike would travel that many mm in 1 pedal (assuming 1 pedal per second). Since the gear ratio is 1.6, you will need to DEVIDE by 1.6 to find how far it actually travelled with 1 pedal. This will tell you the circumference of the wheel!
To find how many times the rear-wheel turns in first gear when the pedals turn 140 times, we need to use the given ratio of 7 to 11.
First, let's set up a proportion using the given ratio:
Pedal turns / Rear-wheel turns = 7 / 11
We know that the pedal turns are 140, so we can substitute that value into the proportion:
140 / Rear-wheel turns = 7 / 11
To solve for Rear-wheel turns, we can cross-multiply:
7 * Rear-wheel turns = 11 * 140
7 * Rear-wheel turns = 1,540
Dividing both sides of the equation by 7:
Rear-wheel turns = 1,540 / 7
Rear-wheel turns = 220
Therefore, in first gear, the rear-wheel turns 220 times when the pedals turn 140 times.