# Homework Help: Big Problem

1. Apr 7, 2004

### delta_mu

A 1.50 kg sled scrapes down a grassy incline where the coefficient of friction is 0.678. The sled moves at a constant speed f 4.50 m/s and it takes 12.5 seconds to travel the entire length of the hill to the bottom.

After the sled passes, a 5.00kg rolling cart (with an effective coefficient of friction of .456) goes down the same hill. At the bottom. the cart crashes into a very massive bale of hay (which does not move so this is not a collision problem). The ha bale exerts an average force of 98.0N on the cart. Calculate how far into the hay bale the cart goes before stopping.

[Hints: find angle of incline; length of incline; acceleration of cart; speed at bottom of incline]

I recieved for the angle: 34 degrees
the length of the incline: 2.78m
acceleration of cart: 1.78m/s squared
speed at bottom: 3.15 m/s

Please inform me if I am wrong on any of those, and please help me to calculate the distance the cart travels in the hay before it stops.

2. Apr 7, 2004

### Chi Meson

Delta Mu:

This is a take-home EXAM. Help from others was specifically forbidden. THis includes people you do not know.

Last edited: Apr 7, 2004
3. Apr 7, 2004

### Chen

Hah! This is funny. Good thing you didn't use your real name...

Well, not knowing if you really are his teacher (afer all, what are the odds?) I will just say that:
$$F_{ext}x = \Delta E_m = \Delta E_k$$

4. Apr 7, 2004

### Chi Meson

The odds are good. I tell all my students about this forum and encourage them to seek help with homework. HTis is a question from a test, however, and I would request that no one answer it further.

5. Apr 7, 2004

### Chen

Fair enough. I do appreciate the trust you have in your students, and what I posted can be found in every textbook anyway.