OAR OAR Mechanical Comprehension: Simple Machines 4

Question 1

A second-class lever always has a mechanical advantage:

Accepted Answer

Greater than 1

Answer

Less than 1

Answer

Equal to 1

Answer

Equal to 0

Question 2

Two interlocking gears: Gear 1 has 20 teeth and Gear 2 has 5 teeth. If Gear 1 is the driver, the gear ratio is:

Accepted Answer

0.25

Answer

4

Answer

1

Answer

15

Question 3

Work input always equals work output in an ideal simple machine because:

Accepted Answer

Energy is conserved

Answer

Friction is zero

Answer

Force is always multiplied

Answer

Speed is always reduced

Question 4

A flagpole uses a pulley to raise a flag. This is an example of which pulley type?

Accepted Answer

Fixed pulley

Answer

Movable pulley

Answer

Block and tackle

Answer

Compound pulley

Question 5

If the efficiency of a machine is 80% and the work input is 500 J, what is the useful work output?

Accepted Answer

400 J

Answer

80 J

Answer

420 J

Answer

500 J

Question 6

A longer screwdriver handle (larger radius) makes a screw easier to turn because it:

Accepted Answer

Increases mechanical advantage

Answer

Reduces the pitch of the screw

Answer

Decreases the thread friction

Answer

Shortens the travel distance

Question 7

Which simple machine would be MOST useful for raising a heavy barrel into a truck bed?

Accepted Answer

Inclined plane (ramp)

Answer

Wedge

Answer

Fixed pulley

Answer

Wheel and axle