Answer the following questions.
(a) What is a simple machine? Give any two examples.
(b) Enlist the different types of simple machines used at your house.
(C) In how many ways do simple machines make our work easier?
(d) How can a simple machine lift a heavy load with small effort?
(e) Define pulley. What is the use of a pulley?
(f) How does wheel and axle work?
(g) For what purpose are the inclined planes used? Write the simila between an inclined plane and a screw.
(h) What is wheel and axle? Write its use.
(i) What is wedge? Write its use.
(j) What is jackscrew? write its use
Answers
Answer:
(a)A machine with few or no moving parts that is used to make work easier (provides a mechanical advantage). For example, a wedge, wheel and axle, lever, inclined plane, screw, or pulley.
wheel and axle: A simple machine that reduces the friction of moving by rolling.
(b)The inclined plane.
The lever.
The wedge.
The wheel and axle.
The pulley.
The screw.
(c)There are three ways simple machines make work easier: by increasing the distance through which force is applied, by changing the direction of applied force, or by multiplying force of speed of the energy applied.
(d)The pulley is normally fixed to a support above the load. The load is tied to one end of the rope and the effort is applied at the other end. Such a pulley makes our work easier by simply changing the direction of the force, i.e. a load is lifted up using a downward effort.
(e)A pulley is a wheel on an axle 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.
(f)The wheel and axle consists of a round disk, known as a wheel, with a rod through the centre of it, known as the axle. This system uses angular momentum and torque to do work on objects, typically against the force of gravity. The wheel and axle simple machine is closely related to gears.
(g)An inclined plane is used to make work easier by creating mechanical advantage. The inclined plane makes work easier by reducing the amount of effort that must be applied to raise or lower a load. This is done by increasing the distance along the length of the slope that the load will travel.Like a wedge, a screw is a simple machine that is related to the inclined plane. A screw can be thought of as an inclined plane wrapped around a cylinder. This spiral inclined plane forms the threads of the screw. When you twist a screw into a piece of wood, you exert an input force on the screw.
(h)Wheel and axle, basic machine component for amplifying force. In its earliest form it was probably used for raising weights or water buckets from wells. Its principle of operation is demonstrated by the large and small gears attached to the same shaft.
(i)Wedge, in mechanics, device that tapers to a thin edge, usually made of metal or wood, and used for splitting, lifting, or tightening, as to secure a hammer head onto its handle. Along with the lever, wheel and axle, pulley, and screw, the wedge is considered one of the five simple machines.
(j)A jackscrew, or screw jack, is a type of jack that is operated by turning a leadscrew. It is commonly used to lift moderately and heavy weights, such as vehicles; to raise and lower the horizontal stabilizers of aircraft; and as adjustable supports for heavy loads, such as the foundations of houses.