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Why a wheel and axle is used?
A wheel and axle is used to lift heavy loads or to turn a body with less force. For example screw driver.
Give a few example of wheel and axle.
Screw driver, Steering wheel of a car, Door knob etc.
Why does a mechanic tighten a nut with a spanner?
Because it is easy to tighten nut with spanner due to large moment arm. Using spanner a nut is more strongly tightened.
Give an example of the use of pulley in daily life.
A pulley is used to take out water from a well.
How does a fixed pulley make the work easier?
A fixed pulley can rotate about a fixed axle. It changes the direction of force. For example hoisting a flag, taking out water from well.
How a moveable pulley differs from a fixed pulley?
A moveable pulley can rotate about a moveable axle. It multiplies the force.
What is the advantage of using a pulleys system?
Moveable pulley helps to life heavy loads with less force, while fixed pulley helps to apply the effort easily by changing the direction of force.
Why a gear has teeth around it?
Teeth are used to grip the teeth of other gear.
A driver gear has 8 teeth and the follower gear has 20 teeth. Does the speed of the follower gear higher or lower than the driver gear?
Speed of follower gear is lower than driver gear.
What will be needed for the follower gear to rotate in same direction as that of driver gear?
A chain is needed to rotate in same direction.
Describe a simple arrangement to demonstrate wheel and axle.
· When we use door knob, we are using wheel and axle.
· The knob is the wheel
· The rod to which knob is attached is the axle.
· Force you apply at knob (wheel) is multiplied at rod (axle)
Describe the working of a pulleys system.
· Pulley system consists of fixed and moveable pulleys.
· Moveable pulley helps in raising heavy loads by applying less force.
· While using fixed pulley in the system, effort can be applied easily.
How can pulleys be used to work like a gear system?
· multiple sheaves in pulleys increase power by the number of sheaves and the number of line reavings.
· A fixed sheave reaved with a movable pulley of one sheave and anchored at the fixed sheave will double the effort.
· Add another fixed sheave and anchor the line at the movable pulley and the effort will be triple
What are the advantages of a gear system?
· A gear is a wheel having teeth around it.
· A gear makes another wheel having similar teeth to rotate without slipping.
· The two gears are either kept close to each other so that the teeth of one gear grip the teeth of the other.
· Thus when one gear is turned, it forces the other gear also to rotate.
Why cranes are used?
· These are used in transport for loading and unloading purpose.
· These are used in construction for shifting materials and equipments.
Which simple machines are used in a Crane?
· A crane has a system of fixed and moveable pulleys.
· A rope rolls over the axle of a wheel and axle.
· The wheel and axle increases the pulling for acting on the rope.
· A large pulling force enables the pulley system to lift heavy loads.
What makes a bicycle to move fast?
The combination of gear system and wheel and axle system makes a bicycle to move fast.
Describe the basic parts of a hand drill.
It is also a combination of many simple machines. The basic parts of a hand drill are Main handle, Driver gear, turning handle, Follower gear, Chuck, Jaw, Drill bit and Tip.