Science project work
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PROJECT
WORK
Science
Submitted
by: Pranish gurung
Submitted
to: Ramesh sir
Submission:27 sep
Contents
1.
By the help of internet look at the different kinds of simple
machines used in our daily life. Observe those machine, download photo of at least five
simple machine. Complete information about. Complete information about
that machine in following pattern.
(Photo of simple machine)
1.
Name of simple machine
2.
Where it is used
3.
How it make our work easier
INTORDUCTION OF SIMPLE MACHINE
Simple machines are those
machines which makes our work easier. Faster and efficient. It helps us to
do work with less effort. They include lever, pulley, inclined plane, screw,
wedge, etc
Machines make our work easier by
changing the force you exert in size, direction or both. No matter how complex
it is, it can be broken into one or more simple machine. Here I am going to
explain about five simple machines
They are as
follows:
1.
Lever
2.
Pulley
3.
Wedge
4.
Screw
5.
Inclined plan
Lever
A lever is a simple machine made of a
rigid beam and a fulcrum. The effort (input
force) and load (output force) are applied to either end of
the beam. The fulcrum is the point on which the beam pivots. When
an effort is applied to one end of the lever, a load is applied at the other
end of the lever. This will move a mass upward. Levers rely on torque for
their operation. Torque is the
amount of force required to cause an object to rotate around its axis. There
are three types of lever they are as follows:
1.
First class lever: If the
fulcrum is closer to the load, then less effort is needed to move the load a
shorter distance. If the fulcrum is closer to the effort, then more effort is
needed to move the load a greater distance. A teeter-totter, a car jack, and a
crowbar are all examples of first class levers. First class levers
are very useful for lifting large loads with little effort.
2.
Second
class lever: In a second
class lever, the load is located between the effort and the fulcrum.
If the load is closer to the fulcrum than the effort, then less effort will be
required to move the load. If the load is closer to the effort than the
fulcrum, then more effort will be required to move the load. A wheelbarrow, a
bottle opener, and an oar are examples of second class levers.
3.
Third
class lever: In a third
class lever, the effort is located between the load and the fulcrum.
If the fulcrum is closer to the load, then less effort is needed to move the
load. If the fulcrum is closer to the effort, then the load will move a greater
distance. A pair of tweezers, swinging a baseball bat or using your arm to lift
something are examples of third class levers. These levers are useful
for making precise movements.
Pulley
A pulley is a
wheel on an axel or shaft that is designed to support movement and change of
direction of a taut cable or belt, or transfer of power between the shaft and
cable or belt. A pulley may have a groove or
grooves between flanges around its circumference to
locate the cable or belt. The drive element of a pulley system can be a rope, cable, belt, or chain.
1. Fixed pulleys
2. Are a very common
pulley. These pulleys are secured to a single spot. The name fixed is because
the pulley itself remains stationary, attached to something like a wall or
ceiling, while the cord or rope passes through it. Because the pulley is fixed,
the force that is applied on the side you are pulling, will be the same amount
of force that is exerted on the opposite side. So why use a fixed pulley
if it’s capabilities are only to exert the same amount of force you,
the user, applies? Well, the fixed pulley is very necessary because it’s
changes the direction of the object; which can be very helpful.
3. Movable
Pulleys: are yet another type of pulley. It differs from the fixed pulley
because the actual pulley machine will move with the load. Because the pulley
moves with the load, a moveable pulley will multiple force which the user
applies to the machine in doing work on an object. These pulleys are often
attached to the actual object, in contrast to the fixed pulley which is
attached to something stationary. Unlike the fixed pulley, the movable pulley
does not change the direction of the object, however it is helpful because of
its multiplication of force on the opposite side of the user. This is ideal for
heavier loads because you have to exert less force but that force gets
multiplied.
4. Compound
Pulley: Systems are a combination of both movable and fixed pulleys.
This type of pulley system has the greatest success in moving your heaviest
loads. It has the greatest multiplication of force. These compound systems can
not only change the direction of the load, but also because
of it’s use of compound pulleys, required less force to be exerted by
the user.
Wedge
A wedge is a triangular shaped
tool, and is a portable inclined plane, and
one of the six classical simple machines. It
can be used to separate two objects or portions of an object, lift up an
object, or hold an object in place. It functions by converting a force applied to
its blunt end into forces perpendicular (normal) to its
inclined surfaces.
Screw
A screw is a simple machine having
threat along its cylindrical surface. The spiral ridge of the screw is called
thread. A screw having less pitch multiplies force more and having more pitch
multiplies force less. Jack screw and screw nail are some example of it. The
screw makes work easier because it increases the distance needed and decrease
the force needed. They are widely used in threaded fasteners to hold objects
together.
Inclined
plane
An inclined plane, also
known as a ramp, is a flat supporting surface tilted at an
angle, with one end higher than the other, used as an aid for raising or
lowering a load. The inclined plane is one of the six
classical simple machines defined by Renaissance scientists.
"Thank you"
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