You can find this problem with supplemental pics on page 6 at http://www.physics.princeton.edu/~mcdonald/examples/ph101_2006/learning_guide_ph101_2006.pdf(adsbygoogle = window.adsbygoogle || []).push({});

Suppose that the maximum possible acceleration for passengers standing on a subway is 0.1 m/s^2 and that two subway stations are 0.7 km apart.

What is the minimum possible time taken between the two subways stations?

___________________________________________________________________

The answer is 170 seconds. I keep getting 118 seconds :(

My calculations are as follows:

x = (0.5)(acceleration)(time^2) where x = 700 meters and acceleration is 0.1

thus, sqrt(2x/acceleration) = time = 118

Can anybody tell me what I am doing wrong?

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

Dismiss Notice

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: I can't get the answer?

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