Question

Usain Bolt is considered to be the fastest person on earth. He holds the record for the fastest 100 m (meters), ,which he ran in 9.58 s (seconds), in 2009. We'll assume that Bolt ran the race at a constant speed.

Which of the following equations, where t represents time in seconds and d represents distance in meters, describe a speed greater than Bolt's record-breaking speed in 2009?
Choose all answers that apply!
A. d=10t
B. d=10.2t
C. d=10.4t
D. d=10.45t

Khan Academy - Rates & proportional relationships

Answer 1

The equation that describes a speed greater than Bolt's record-breaking speed in 2009 is d = 10.2t.

Step-by-step explanation:

The equation that describes a speed greater than Bolt's record-breaking speed in 2009 is d = 10.2t. This equation represents a distance (d) that increases by 10.2 meters for every second (t) that passes. Since the coefficient of t is greater than 9.58 (Bolt's record-breaking time in seconds), this equation represents a speed greater than Bolt's record-breaking speed.