Question

1. the elevators in the landmark tower, in yokohama, japan are among the fastest in the world. they accelerate upward at 3.125 m/s² for 4.0 s to reach their final speed. if these elevators start from rest, what is their final speed?

Explanation:

Step1: Identify the formula for final velocity

The formula for final velocity \( v \) when an object starts from rest (\( u = 0 \)) and undergoes constant acceleration \( a \) for time \( t \) is \( v=u + at \). Since \( u = 0 \) (starts from rest), the formula simplifies to \( v=at \).

Step2: Substitute the given values

We are given \( a = 3.125\space m/s^2 \) and \( t = 4.0\space s \). Substituting these values into the formula \( v = at \):
\( v=(3.125\space m/s^2)\times(4.0\space s) \)

Step3: Calculate the final velocity

Multiplying \( 3.125 \) by \( 4.0 \):
\( 3.125\times4.0 = 12.5 \)
So, \( v = 12.5\space m/s \)

Answer:

The final speed of the elevator is \( 12.5\space m/s \)