The 1992 world speed record for a bicycle (human-powered vehicle) was set by Chris Huber. His time through the measured 200 m stretch was a sizzling 6.509 s, at which he commented, “Cogito ergo zoom!” (I think, therefore I go fast!). In 2001, Sam Whittingham beat Huber’s record by 19.0 km/h. What was Whittingham’s time through the 200 m?

#### Solution:

### Let us first calculate Huber’s speed, which is:

### v_{huber}=\frac{200 m}{6.509 s}= 30.72 m/s = 116 km/h

### Next, we know Whittingham beat Huber by 19 km/h, which means his speed, v_{whittingham}= 110.6 km/h + 19 km/h =129.6 km/h . Converting this to m/s yields 36 m/s. Now, we find the total time taken by Whittingham:

### t=\frac{200 m}{36 m/s} = 5.554 s

###### This question can be found in Fundamentals of Physics, 10th edition, chapter 2, question 6.