The three different types of radius are relevant because the crank wheel radius, chain wheel radius, and wheel radius each contribute to the overall movement of the bike.
First, we need to find the gear ratio, which is the ratio between the number of teeth on the crank wheel (front gear) and the number of teeth on the chain wheel (rear gear). The gear ratio can be calculated using the radii of the crank wheel and chain wheel:
Gear ratio = (Crank wheel radius) / (Chain wheel radius) = 11cm / 4cm = 2.75
Next, we need to find the effective wheel rotation per minute due to this gear ratio. To do this, multiply the pedal rotation per minute by the gear ratio:
Effective wheel rotations per minute = (Pedaling rpm) × (Gear ratio) = 60 rpm × 2.75 = 165 rpm
Now, we can calculate the distance traveled per minute by multiplying the wheel's circumference by the effective wheel rotations per minute. The wheel's circumference can be found using its radius:
Circumference = 2 × π × wheel radius = 2 × π × 35cm = 220 cm (approx.)
Distance traveled per minute = (Wheel circumference) × (Effective wheel rotations per minute) = 220 cm × 165 rpm = 36300 cm/minute
Finally, we can convert the distance traveled per minute into a more standard unit, such as kilometers per hour:
36300 cm/minute * (1 m/100 cm) * (1 km/1000 m) * (60 minutes/1 hour) = 21.78 km/h
So, K is going at a speed of approximately 21.78 km/h.
J and K are cycling together. K is riding a bike with a wheel radius of 35cm, crank
wheel radius 11cm and chain wheel radius 4cm. She is pedalling at 60 rpm. How
fast is she going?
-->What is the significance of giving 3 different types of radius?
--> know to find circumference and multiply it by rpm to find linear velocity
--> but what to radius to use/how?
1 answer
1 answer