# Comparing the deceleration of a squirrel to a WW2 airmen

## Homework Statement

Compare the deceleration of the squirrel to airmen. The squirrels velocity being 7.67 (m/s) ignore air resistance, stopping distance of 3.9 cm, deceleration of an airman being 486 (m/s^2), velocity being 54 (m/s) and stopping distance of 3.0 m.

## The Attempt at a Solution

Confused in general I used some d formula's along with some velocity formula's, I got -0.01 and -0.02

Bystander
Homework Helper
Gold Member
Google "terminal velocity" and get back to us with what you're not understanding.

I just don't get how you would find the deceleration and if you are given the deceleration of the airmen than why do they give you the extra numbers?

Is this really the whole question? Are you paraphrasing? Was there an earlier part that gave some context? Out of context it seems almost incoherent.

You have no relevant equations and I have no idea what you mean by -0.01 and -0.02

In any case, there is certainly enough information to calculate the deceleration of the squirrel, and the deceleration of the airman is given explicitly. Show us some equations you think might apply and show us what you tried and maybe we can help.

Also, I’m not sure what good looking up terminal velocity will do. For some reason you have the phrase “ignoring air resistance” so if that’s true this must not be about terminal velocity. If the title of the post is correct the problem gives all the information you need anyway.

Slightly OT but, IIRC, an air-gunner fell out of damaged bomber over Germany *without* time to attach parachute pack to harness.

He fell through the thick foliage of snow-covered pines into a deep snow-bank. Battered and bruised, but unbroken and very much alive.

Was nearly shot as spy before clued-in Luftwaffe officer realised what had happened and rescued him...

Ah-Ha !

Also links to other chute-less survivors...

Sorry, so that is the second part of the equation and I already got the answer for part one being 7.67 and the first part of the question was asking what is the velocity of the squirrel before hitting the ground from 3.0 m. To be honest I used the equation V^2 = Vnot + 2ad. the -0.01 and -0.02 were my answer's, but I knew they were wrong since that does not make any literal sense.

CWatters
Homework Helper
Gold Member
The problem seems fine to me.

You haven't quoted any relevant equations or assumptions. Are you familiar with the SUVAT or similar equations for constant acceleration/deceleration?

The problem statement gives you the initial velocity, final velocity and the stopping distance for the squirrel. Ths is enough to work out the deceleration.

CWatters
Homework Helper
Gold Member
I just don't get how you would find the deceleration and if you are given the deceleration of the airmen than why do they give you the extra numbers?
You are complaining thy have done half the work for you :-)

Perhaps that is to help you identify or make assumptions that you can also apply to the squirrel.

CWatters