Science 800B Lesson 25 - Wheel and Axle, Pulleys, Gears

A certain block and tackle system has four supporting strands so its IMA is _______.

4.

Gear C will turn in a _____. clockwise direction counterclockwise direction

Clockwise direction.

Gear B will turn in a _____. clockwise direction counterclockwise direction

Counterclockwise direction.

Gears of different sizes change the _____ and _____. direction efficiency M.A. power speed

Direction, speed.

Gears of the same size change ___________ of motion.

Direction.

An "ideal" mechanical system with 100% efficiency is possible if designed properly. True False

False.

Raising a heavy weight with a pulley system using very little effort is an example of creating energy. True False

False.

The efficiency of the wheel can be found by dividing the IMA by the AMA. True False

False.

The energy lost to friction is destroyed. True False

False.

The pulley has a greater energy loss to _____________ than does the lever.

Friction.

The Law of Conservation of Energy applies to _____. ideal systems only real systems only ideal and real systems

Ideal and real systems.

In a real pulley system, the work input must be ______________ the work output.

More than.

Is there any mechanical advantage in using a single fixed pulley? Yes No Sometimes

No.

A wheel with a radius of 25 centimeters has an axle with a radius of 5 centimeters. The IMA of this wheel is ____________ ___ ______.

None of these.

In the above illustration, why is the input force only half of the weight to be lifted? Fo is reduced by ½ Weight moves through twice the distance of Fi the fixed hook carries ½ the weight the pulley is holding ½ the weight

The fixed hook carries 1/2 the weight.

A wheel and its axle have the same axis. True False

True.

In a real system of levers, wheels, or pulleys, AMA is always less than IMA. True False

True.

When using the wheel and axle, the input force moves through a greater distance than the output force. True False

True.

In an ideal frictionless system, the work input equals the __________ ___________.

Work output.

The IMA of a wheel and axle could be increased by increasing the size of the __________ and/or _____________ the size of the axle.

wheel, decreasing.