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

A person trips against a table, causing a glass to fall off the edge. An excellent human reaction time is 0.25 seconds. In that time, how far wil the glass fall? Assume that immediately (after 0.25 s has elapsed) begin to acclerate your hand so that you grab the glass when it is 6 in from the floor. What constant acceleration was necessary, and how fast was your hand traveling when you contacted the glass? Assume your hand moved in a straight line.

2. Relevant equations

3. The attempt at a solution

I find the position vector of the hand to be:

I get the position vector of the glass to be:

I need to find the time it takes for the glass to fall to y=0.5:

So the hand only has 0.46 seconds to reach the glass. However, when I plug this into the position vector of the hand to find a_x and a_y and find the magnitude of the acceleration, I get like twenty-something ft/s^2 which is far below the correct answer of 241 ft/s^2. What am I doing wrong?!

Please help asap!

**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: Catching a glass falling to the ground

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