Question

V2 = 30 m/s, V1 = 0 m/s, T = 18s.

What is the final velocity (V2) if an object starts from rest (V1) and accelerates at a constant rate for 18 seconds?
A) V2 = 30 m/s
B) V2 = 36 m/s
C) V2 = 18 m/s
D) V2 = 54 m/s

Answer 1

The final velocity (V2) of an object accelerating at a constant rate from rest for 18 seconds remains 30 m/s, so the answer is A) V2 = 30 m/s.

Step-by-step explanation:

The student is asking about an object's final velocity (V2) when it starts from rest and accelerates at a constant rate for a certain amount of time. In this problem, we are given an initial velocity (V1) of 0 m/s, indicating the object starts from rest, a final velocity (V2) of 30 m/s, and a time (T) of 18 seconds to reach this final velocity. The formula to calculate acceleration (a) given initial velocity (V1), final velocity (V2), and time (T) is:

a = (V2 - V1) / T

Substituting the given values into this formula, we find that a = (30 m/s - 0 m/s) / 18 s = 1.67 m/s². Since the object is accelerating at this constant rate, the final velocity after 18 seconds will remain 30 m/s. Therefore, the correct answer to what is the final velocity if an object starts from rest and accelerates at a constant rate for 18 seconds is:

A) V2 = 30 m/s