# Science Homework - O. Henry Science ```Simple Machines &amp;
Science Homework
Name: ____________________________________
Digestive System
Due Friday, December 9th
Date: _________________ Period: __________
Part I: Force
Recently, we learned about the skeletal and muscular systems, which work together to generate movement. More
importantly, they work together to generate force. A force is anything that causes an object to change speed,
change direction, or change shape. When you lift a cell phone to your ear, your muscles create the force needed to
move the phone. When you throw a ball or kick a box on the floor, again your muscles are generating a force that
causes the ball or box to change direction, speed, or shape.
1) What is force?
A force is _____________________________________________________________________________________
________________________________________________________________________________________________________________________.
2) Which image below does not show the application or use of force?
A. Pushing boxes
up a ramp
B. Kicking a
soccer ball
C. Inflating a
balloon
on desk
Part II: Work and Simple Machines
Sometimes, a force is needed that is greater than what are muscles can provide. Therefore, humans created simple
machines to help reduce (or lessen) the amount of force and work needed to move or change the shape objects.
Visit the website below and complete the game to learn about 4 common simple machines. Copy the full
definition for each simple machine and draw a picture of it.
You may also search Google using the words “Chicago simple machines”
Machine
Definition
Sketch
Ramp
________________________
________________________
______________________
PART III: Energy, Work, and Force
Work might happen when an object moves a certain distance under force. Work here means mechanical work,
and it is measured in units called joules. Work (which is measured in units called joules), is equal to force
multiplied by distance. Note that the force and distance here have to be in the same directions. That is, the force
should be exerted in the direction in which the object moves.
What is work?
What unit is used to measure work?
Does the force exerted have to be in the same direction that the object moves for WORK to be done?
There are different ways to accomplish work, such as making use of inclined planes, ramps or simple machines.
Simple machines allow you to decrease the force you need to do work by increasing the distance that the force
is exerted. Thus the total amount of energy or work remains the same.
Formula for work:
Work = Distance x Force
Units:
Work : Joules
Distance : meters
Force : Newton
1. Using a force of 50 N, you push a cart 10-m across a classroom floor. How much work did you do?
Friction happens between the contacting surface and a moving object. This acts as a resister to prevent the
relative motion between the surface and the object. When we move an object, the direction of this friction force
is opposite to the direction where we push the object. Hence this resisting force needs to be overcome in order
to successfully move the object. Forces affect motion. There are lots of examples you may already notice in
your daily life. The process of seedling growth demonstrates a greater upward force than the gravity, which is
working in the opposite direction. This is the reason that the plants can break through the soil
```