Acceleration PREFLIGHT

The following three questions refer to the material you were to read in preparation for the lesson.

You may change your mind as often as you wish. When you are satisfied with your responses, click the SUBMIT button at the bottom of this page. Don't submit more than once. (If you absolutely HAVE to resubmit it, put a note on the end to that effect.)

# 1. Multiple Choice

Which of the following weighs about 1 N?
this book
an apple
a mosquito
you

# 2. Newton's Laws

(See the bottom of the page for the animation, I can't put these Java animations into a HTML form yet...)

What is the force of the large block on the small block in each case? Do you expect both forces to have the  same magnitude?

# honors extra

(See question 10). A stone hangs by a fine thread from the ceiling and a section of the same thread dangles from the bottom of the stone. If a person gives a sharp pull on the dangling thread, where is the thread likely to break: below the stone or above it? What if the person gives a slow and steady pull? Explain your answers.

Below is a space for your thoughts, including general comments about today's assignment (what seemed impossible, what reading didn't make sense, what we should spend class time on, what was "cool", etc.):

You may change your mind as often as you wish. When you are satisfied with your responses, click the SUBMIT button.

I received no help from anyone on this assignment.

 Animation 1 Animation 2

#### Description

A 1.5-kg block receives a  push and in the process pushes against a 4.5-kg block as shown in animation 1 (position is in meters and time is in seconds). Conversely, in animation 2, the same 4.5-kg block receives the same push, now from the opposite direction, and in the process pushes against the 1.5-kg block as shown. All surfaces are frictionless.

#### Credits

Physlet problem authored by Mario Belloni

2000 by Prentice-Hall, Inc. A Pearson Company