Machines

pub is starting out early this morning for a bicycle tree brother Bob can't ride a bicycle so he has to stay home but he runs up the street with anyway no use running he'll never keep up with the boys around the corner and the way they go how can they move so much faster on a bicycle and still not work so hard as Bob when he run the Rangers are using simple machines to help them move faster and easier machines are helpers and they make hard jobs easier for us to do the bicycle uses several simple machines working together one of these is called the wheel and axle the steering wheel in an automobile is a wheel and axle to it is fastened to a long rod that runs down to the front wheels it's much easier to turn the rim of this big steering wheel than to try to turn the small rod in the center wheel and axle machines make our work much easier a doorknob is a wheel and axle the pencil sharpener is another wheel and axle machine by turning the handle in a circle like a wheel you are making the axle move the blades that sharpen your pencil when we want to lift things higher than our heads we can do it by pulling down on a rope that is running up over a pulley every morning when the flag is raised on the flagpole at school a pulley is used to lift it to the top the pulley is another kind of simple machine that helps make work easier here's a pulley that helps build a house the man on the roof needs more tar so his helper down on the ground hooks a pail of the heavy tar on to a rope then pulls on the end to send the bucket up to the man on the roof their work is made much easier by the pulley bullies can help mother two apartment houses sometimes have wash line bullies so that people upstairs do not have to come down to the backyard to hang their wash the line runs around the pulley and can be moved out into the air the cable on back of a tow truck that lifts the front end of a car off the street is going over pulley when the man starts the motor the cable runs around these pulleys and whines onto a big wheel the job of lifting a heavy object becomes easier when we use one or more simple pulley a lever is another kind of simple machine that helps make our work easier by pushing down on the long end of the bar this man can make the short end lift the nails and the lid from the box with very little work a hammer is a lever so is a broom a baseball bat a crowbar out in the country the Rangers stopped at a wayside park for a refreshing drink of water the handle of the pump is a simple machine that lifts the water from beneath the earth it too is a lever by pushing down on the long end of the handle the boy can make the short end lift the rod that brings the water up into the pump a lever is a bar that moves back and forth on a fixed point and helps us do things with less work a flat surface is called a plane a sloping surface is called an inclined plane and this is another kind of simple machine this man rolling a barrel up a plank to get it onto a truck is using an inclined plane it would be very hard work to lift the barrels straight up from the street to the truck but by using a sloping surface and pushing it a little farther the man can do the job much easier a stairway is an inclined plane also or it lets you go to an upper floor with very little effort the Rangers have come to the big hill and making a bicycle go up the road is hard work but see how much harder it would be to try to ride the bicycle straight up the side of the hill the road is built along a gradual slope so that people can travel to the top easier by going a little farther around on an inclined plane this Ranger is trying to drive a stake into the ground he's having trouble because the end of the stick is flat when he takes a knife and cuts to angles on the end of the stick he can drive it into the ground very little trouble the end of the stick has been made into a wedge a wedge is another kind of simple machine that helps make our work easier the knife itself is a wedge with one edge very thin for cutting and the other edge thick and acts as a wedge to even the end of a nail or tact is a wedge for it comes to a point and soul makes it easier to drive into wood a plow is a wedge also or as the tractor pulls it forward in the field the thin edge cuts into the earth and put it aside the Rangers have met a man whose car has a flat tire he is raising a corner of the car with a screw jack so that he can change the wheels with the screw jack this man is lifting a very heavy weight with very little work so we have come upon another simple machine the screw that helps do our work easier the screw is really an inclined plane that wins round and round up a bar the man is making the screw move by turning a handle as the screw turns it rises slowly and lift the heavy car that is resting on top of it the airplane propeller is a screw also it pulls the plane across the sky the bolt that holds the wheel onto the frame of the bicycle is a screw the screw and a vise holds things together too so does the screw cap on a jar of fruit all machines are one or another of only six different kinds of wheel and axle lever the pulley the inclined plane the wedge and the screw they help push pull or move things from one place to another all machines from the lawnmower to the railroad engine use one or more of these six kinds of simple helpers even our playground ID is a machine an inclined plane your roller skates are mostly wheel and axle every day we use simple machines in our work or play and every day they are doing things for us to make living easier and simpler