Question

Usain Bolt, while training, starts from rest and reaches a 12 m/s velocity while accelerating at 3.5 m/s2​ ​. What was the distance he covered and how long he took to do it?

Answer 1

Usain Bolt covered approximately 20.3 meters in about 3.43 seconds to reach a velocity of 12 m/s with an acceleration of 3.5 m/s².

Step-by-step explanation:

To find out how long Usain Bolt took to reach a velocity of 12 m/s with an acceleration of 3.5 m/s2, and the distance he covered, we can use the kinematic equations for uniformly accelerated motion. The time t can be calculated using the formula v = u + at, where v is the final velocity, u is the initial velocity (0 m/s since he starts from rest), and a is the acceleration. To find the distance s covered, the equation s = ut + (1/2)at2 is used.

Using the first equation, we find:
t = v/a = 12 m/s / 3.5 m/s2 = 3.43 seconds (approximately)

Now, using the second equation:
s = 0 * t + (1/2) * 3.5 m/s2 * (3.43 s)2 = 20.3 meters (approximately)

Therefore, Usain Bolt covered a distance of approximately 20.3 meters in about 3.43 seconds while reaching a velocity of 12 m/s.