(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

An airplane touches down at a speed of 100m/s. It travels 1000 metres along the runway

while deceleration at a constant rate before coming to rest. How long did it take the airplane to come to rest on the runway?

Xi=0m/s Xf=1000m Vix=100m/s

2. Relevant equations

Xf=Xi+Vixt

3. The attempt at a solution

1000=0+100t

t=10s

Why is the answer 20 s? and why does this formula fail?

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Classical Mechanics Questions

**Physics Forums | Science Articles, Homework Help, Discussion**