machines [1] [general] [comprehension quiz]

A machine is a device that does a physical task. There are two types - simple and complex. A simple machine makes work easier by magnifying or changing the direction of the force. A complex machine often uses many simple machines in combination. There are six types of simple machines. Here is an example of an INCLINED PLANE being used in Egyptian times to move huge stone blocks up a slope. Here is an example of a LEVER which has been used for thousands of years in desert regions as a shaduf to raise water from wells. Here is an example of a WHEEL and AXLE which again has been around for thousands of years but seen here on a Roman chariot. Here is an example of a PULLEY used as a means of raising heavy sails on a ship. Here is an example of a WEDGE being used as an axe by Viking warriors. Here is the final example of a SCREW invented thousands of years ago by the Greek Archimedes. Here it is being used to transport water upwards.

1. Which simple machine is a car jack ? inclined plane pulley screw 2. Which simple machine is a ramp ? lever inclined plane wheel and axle 3. Which simple machine is a lift ? pulley screw wedge 4. Which simple machine is a human arm ? lever inclined plane wheel and axle 5. Which simple machine is a door knob ? pulley wheel and axle screw

There are 9 pictures in a grid. As you hover over each picture a blue screen appears on which there is some information about what is being shown in the picture. Read this information and look at each picture to make sure you understand what is being shown. If you want to check how much you understand try the quiz on the right hand side. To start the activity again just refresh the page.