Term 4 Notes Forces and Motion & Engineering

Motion Motion: is the change of position or location over a certain length of time. Basically motion is the movement of an object. Motion is the result of an applied force. In Physics motion is usually measured in terms of velocity and speed.

For an object to move there must be a force that is applied to it. No object can move on it’s own. An object that is not moving is said to be at rest.

Types of Motion There are three types of motion. 1)Translational Motion This is the when an object moves in a straight line. Ex: Car, bike 2) Rotational Motion This is when an object moves in a circle. Ex: Merry-go-round, wheel 3) Spiral Motion This is when an object moves in spiral. Ex: Cork screw, screw

All the dots in the animation are showing translational motion All dots are moving in a straight line. But are travelling in different directions.

The wheels are showing rotational motion. Wheels are moving in a circle.

The blade is moving in a spiral motion The blade is moving in a circle and straight at the same time this produces a spiral.

Force In Physics a force is any action that allows an object to move. Ex: pushing a shopping cart A force can also change the speed or direction (trajectory) of an object that is already in motion. Ex: curling, pool, bocce Finally a force can deform (change the shape) of an object. Ex: stretching an elastic, leggings

Types of force There are five types of force 1) Tension This force will stretch an object Ex: bow and arrow, elastic

2) Compression This force will compress (squeeze) an object. Ex: squeezing a sponge, crushing a can

3) Torsion This force will twist an object Ex: opening a jar, twisting your ankle.

4) Flexion This is the force that will bend an object. Ex: your spine, pole vault

5) Shearing This is the force that will tear an object. Ex: tearing a piece of paper, earthquake

Effects of a Force As mentioned above an object needs a force to move. No object will move on its own. Therefore, the effects of a force is motion. Even the human body is a complex system of forces. In one movement the human body can experience all five forces.

Mechanisms that transmit Motion Motion can be transmitted to other components in a system. A mechanism that transmits motion is will transfer motion of the same type to another component in a system. In many systems oil and water are used as these mechanisms. Ex: Hydraulics and hydro dams

Other components can be used to transfer motion. Components like; gears, pulleys, belts, and chains all work together to transfer motion. Describe how motion is transmitted in a bicycle

1. Force applied by the rider’s legs. Which causes the pedals to move (translational motion) 2. The arms of the pedals move in a circle (rotational motion) 3. The chain move backwards (translational motion) towards the back gears. 4. The back gear rotates which is attached to the rear wheel. 5. This allows the bicycle to move forward

Simple Machines A simple machine is a mechanical device that will change the direction of a force. A simple machine uses one type of force to move an object. There are 6 classical simple machines; lever, pulley, wheel & axle, inclined plane, wedge, screw Provide one example of how each would be used

1. Lever: Hammer, letter opener, car jack 2. Pulley: clothes line, elevator 3. Wheel & Axle: Car, bike 4. Wedge: Axe, chisel 5. Inclined plane: ramp, see-saw 6. Screw: screw, cork screw

Mechanisms that bring about a change in Motion Any object that is in motion can have its speed and direction changed. This change would occur if another force is applied to this object. An object being squeezed then stretched. Ex: dough Ex: A ball bouncing off a wall Ex: Car crash.

Drawings Drawings, images, and pictures are used in our everyday lives. Drawings can be used to represent an event, action, person, or a law. In many circumstances a drawing or picture can be clearer than a verbal or written explanation. Some images have become so recognizable that no words are needed at all.

Identify these images

Types of Drawings Drawings are most often used in construction. Drawings serve to illustrate how various parts will connect with one another. Furthermore, drawings will show dimension. Finally a drawing can depict how to put an object in motion.

Drawings can also serve as instructions in the making of a technical object. There are three types of drawings one can use. 1) Sketch A sketch is a freehand drawing that depicts a design of an object. It will show the shape and some dimensions of an object. It will also help in the creation of other drawings

2) Design Plan A simplified drawing showing the function and operating principles of an object. This type of drawing does not include any measurements or list of materials.

3) Technical Drawing Is a simplified drawing showing the materials and steps to get the object to its final functioning form. It may also be necessary to include several angles (front, top, side views) This type of drawing also includes how different pieces will be connected. There are 12 basic lines that one can use in a technical drawing

Manufacturing Process Sheet A manufacturing process sheet is a document similar to a set of instructions. This document includes every step required to manufacture a technical object. It provides the order in which steps need to be carried out. It also gives the time allotted for each step

Materials, Raw Materials, and Equipment The manufacturing of technical objects requires a diverse set of materials. Material: any substance used to make things. Materials are classified by the origin of their raw materials. Materials include things like: wood, glue, staples, paper, metals, etc.

Raw materials: a natural material that has not been transformed into materials that can be used. Raw materials are unprocessed. There are three major categories of raw materials. 1. Wood substances: hard and soft wood 2. Minerals: Iron, copper, steel, etc. 3. Crude oil: plastic, polymer, nylon, etc.

Equipment: are the tools, instruments, and machines that create technical objects. Equipment could be as simple as a pencil, scissors, toothpick, etc. Equipment are technical objects themselves. Every piece of equipment is made up of materials and followed a process in its manufacturing.

Specifications Specifications is a document that provides a detailed description of needs and demands. A technical object will have a specific function, therefore it needs to be built in a certain way. For example, a bridge must be able to withstand strong winds, precipitation, and natural hazards.

Lab Exam Review

Mass and Volume To measure the volume of a liquid simply read the measurement off of a graduated cylinder. NOTE: be sure to read the bottom of the meniscus. Volume is the amount of space taken up by an object

Volume of a cube: V= s x s x s (All sides of a Cube are equal) S S S Volume of a rectangular prism: V= l x w x h w h l

To measure the volume of an irregular shaped object, ex: rock, use the water displacement method. Water displacement method: 1. Fill a graduated cylinder with a known quantity of liquid. 2. Place the object in the cylinder 3. Follow this formula V= V f (water with object) – V i (just water)

Mass is very easy to calculate. Simply place the object on a scale or balance. Use of the triple beam balance will be explained in the lab.

Example Problems 1. Volume of a cube with a side of 5.7 cm. 2. Volume of a rectangular prism with a length of 10cm, width of 6.3cm, and height of 2cm 3. Volume of a rock that raised the water in a graduated cylinder(GC) 10ml from the original 25ml.

Density Mass and volume are not considered characteristic properties. This is due to the fact that many objects could have the same mass and volume. In these cases one would have to calculate the density of the objects. Density: measures the amount of matter (particles or stuff) in a substance.

To calculate the density of an object one must know the mass and the volume. Density is calculated using the following formula: D = m/v The formula reads density is equal to mass divided by volume. The units for density are g/ml

Example problems 1. Density of an object with a mass of 8.9g and a volume of 3.3ml. 2. Density of a substance with a mass of 130g and a volume of 40ml. 3. Density of a cube with a mass of 25g and a side of 1.3cm. 4. Density of a bracelet with a mass of 8g and raised the water in a GC 3ml from 10ml.

Acidity and Alkalinity pH is the measure of how acidic or how basic (alkalinity) a solution is. pH scale measures solutions (liquids) The pH scale has a range of If a solution falls into the 0-7 range it is an acid, 7-14 it is a base (alkaline). 0 = battery acid, 14 = drain cleaner If a solution is 7 it is neutral ex: pure water.

Using a microscope: Page 311 in your textbooks