Final answer:
A rocket increasing its speed from rest to 42.0 m/s over 6.30 seconds has a constant acceleration. Calculating the acceleration using the formula (a = Δv/Δt) yields a positive value of 6.667 m/s².
Step-by-step explanation:
The question regarding a rocket launched from rest steadily increasing its speed relates to calculating acceleration. The rocket's increase in speed from 0 to 42.0 m/s over a 6.30 s interval indicates that the acceleration is constant, since acceleration is the rate of change of velocity with respect to time. Using the formula for acceleration (a = Δv/Δt), where Δv is the change in velocity (42.0 m/s) and Δt is the change in time (6.30 s), it can be calculated as follows:
a = Δv/Δt = 42.0 m/s / 6.30 s = 6.667 m/s²
This result shows that the rocket's acceleration is constant and positive over the given time interval. Therefore, Option B: Acceleration is constant correctly answers the student's query.
The rocket is steadily increasing its speed over a given time interval, which indicates that its acceleration is constant. This means that the rocket is experiencing the same acceleration throughout the entire 6.30 s interval.
Acceleration is defined as the rate of change in velocity over time, so if the velocity is increasing at a steady rate, the acceleration must be constant.
Therefore, the correct answer is B. Acceleration is constant.