Question

When running a 100-meter race, Usain Bolt reached his top speed when he was 30 meters from the starting line and had been running for 4.8 seconds since the start of the race. He passed the 70-meter line of the race when he had been running for 7.2 seconds since the start of the race. What was the change in time,

Δt, as the number of seconds since the start of the race increased from 4.8 seconds to 7.2 seconds?

a.Δt=2.4 seconds
b.Δt=2.8 seconds
c.Δt=3.2 seconds
d.Δt=3.6 seconds

Answer 1

The change in time, Δt, as the number of seconds since the start of the race increased from 4.8 seconds to 7.2 seconds for Usain Bolt is 2.4 seconds.

Step-by-step explanation:

To calculate the change in time, Δt, we simply subtract the initial time from the final time. In this case, Usain Bolt's initial time when he reached his top speed was 4.8 seconds, and the final time when he passed the 70-meter line of the race was 7.2 seconds.

Δt = final time - initial time
Δt = 7.2 seconds - 4.8 seconds
Δt = 2.4 seconds

Therefore, the change in time as the number of seconds since the start of the race increased from 4.8 seconds to 7.2 seconds is 2.4 seconds. The correct answer is (a) Δt=2.4 seconds.