# Converting m/s^2 to km/h^2 ?

An airplane starts from rest and accelerates at a constant rate of 3.00 m/s^2 for 30.0s before leaving the ground. What is the airplanes velocity in km/h at the end of this interval?

Vi=0m/s
Vf=?
a=3m/s^2
Δt=30s

Not sure if I did it right or if im also supposed to convert the acceleration to km/h before plugging into equation. If so, how do i convert 3m/s^2 to km/h^2?? Please help

Last edited:

Just get the final velocity in m/s then convert to km/h. That would be the simplest thing to do.

berkeman
Mentor
An airplane starts from rest and accelerates at a constant rate of 3.00 m/s^2 for 30.0s before leaving the ground. What is the airplanes velocity in km/h at the end of this interval?

Vi=0m/s
Vf=?
a=3m/s^2
Δd=1350m
= 1.35km

Vf^2=Vi^2 + 2aΔd
Vf=2.84km/h

Not sure if I did it right or if im also supposed to convert the acceleration to km/h before plugging into equation. If so, how do i convert 3m/s^2 to km/h^2?? Please help

You are given acceleration and time, not acceleration and distance. You need to use a different version of the kinematic equation -- one that relates velocity to acceleration and time...

And to do any units conversion, just multiply by "one". So if I wanted to convert inches to mm, for example, I'd multiply by 1 = (25.4mm/1 inch), cancel the "inch" units on the top and bottom of the fraction, and be left with the distance in mm.

AlephZero