Science 8 Year in Review- Unit D

Science 8 Year in Review- Unit D

Multiple Choice

A simple machine that converts rotational motion into linear motion is:

• A lever

• A screw

• An inclined plane

• A wedge

Multiple Choice

As we have evolved as a society, we have improved our ability to assemble machines. What we used to do with simple machines, we now do more effectively with:

• Different simple machines

• Complex machines

• Subsystems

• None of the above.

Open Ended

The function of a bicycle is:

Multiple Select

Select all of the subsystems that exist within a bicycle:

• Steering system

• Braking System

• Cooling System

• Speed Changing system

Multiple Select

Select all the simple machines that exist within a bicycle:

• Wheel and axle.

• Lever

• Pulley

• Inclined plane

Multiple Choice

The most likely source of energy for any device plugged into an outlet is:

• Mechanical energy

• Thermal energy

• Chemical energy

• Electrical energy

Multiple Choice

The primary linkage in a bicycle is the:

• Chain

• Transmission

• The pedals

• Brake system

Multiple Choice

A device that requires 3m of input distance to get 0.5m of output distance has a speed ratio of:

• 1

• 3

• 6

• 9

Multiple Choice

A machine that is able to move an object that weighs 36 Newtons with 6 Newtons of force has a mechanical advantage of:

• 6

• 30

• 36

• 42

Multiple Choice

A pulley system that has a speed ratio of 3 and a mechanical advantage of 2 has an efficiency of

• 33%

• 67%

• 60%

• 30%

Multiple Choice

If you lift a box onto your desk that is 0.4 meters off the floor, using 50 Newtons of force, how much work are you doing?

• 20 J

• 125 J

• 50.4 J

• 49.6 J

Multiple Choice

When determining the efficiency of a certain machine, the students found that 1600J of work were needed to get 1200J of work from the machine. The efficiency of this machine was

• 2800 J

• 400 J

• 75%

• 25%

Multiple Choice

Pascal’s Law states that pressure applied to an enclosed fluid is transmitted

• to the walls of the container which double the pressure.

• equally in all directions throughout the fluid.

• by the transfer force in the fluid.

• to the opposite piston where it increases the force.

Multiple Choice

The disadvantage of the hydraulic system is similar to the disadvantage of levers and pulleys. To increase the force on the output piston, the input piston has to

• have less friction.

• create more pressure.

• move a greater distance.

• be attached to a load.

Multiple Choice

During the research phase, when a device is improved upon, certain criteria are taken into account. Of the criteria listed below, which would be the least important

• function

• efficiency

• effectiveness

• convenience