Mechanical Comprehension · Practice test 2

Question 1Not answered

In a gear train with two meshing gears, if the first gear rotates clockwise, the second gear will rotate

1. clockwise
2. it will not rotate at all
3. in the same direction only if both gears are equal size
4. counterclockwise

Question 2Not answered

A wheel and axle has a wheel radius of 12 inches and an axle radius of 3 inches. What is its mechanical advantage?

1. 9
2. 36
3. 4
4. 0.25

Question 3Not answered

In a pulley system, four rope sections support the movable block. What is the mechanical advantage?

1. 4
2. 2
3. 8
4. 1

Question 4Not answered

A force of 200 pounds presses on a piston with an area of 8 square inches. What is the pressure?

1. 25 pounds per square inch
2. 1600 pounds per square inch
3. 208 pounds per square inch
4. 0.04 pounds per square inch

Question 5Not answered

Scissors are best described as a pair of which class of lever?

1. second class
2. third class
3. first class
4. not a lever, a wedge instead

Question 6Not answered

A block and tackle has 5 rope segments holding up a 400 newton load. Ignoring friction, what effort force is needed to lift it?

1. 2000 newtons
2. 400 newtons
3. 40 newtons
4. 80 newtons

Question 7Not answered

A pair of tweezers is an example of which class of lever?

1. First class
2. Second class
3. Third class
4. They are not levers at all

Question 8Not answered

Using a bottle opener where the rim of the cap acts as the fulcrum is an example of which class of lever?

1. second class
2. first class
3. third class
4. a pulley, not a lever

Question 9Not answered

In a hydraulic press the small piston has an area of 2 square inches and the large one 10 square inches. A force of 50 pounds on the small piston produces what force at the large one?

1. 50 pounds
2. 250 pounds
3. 10 pounds
4. 1000 pounds

Question 10Not answered

A steel ship floats even though steel is denser than water because

1. its hollow shape displaces enough water to equal the ship's total weight
2. steel becomes less dense once it touches water
3. all metals float in salt water regardless of shape
4. the ship has no weight while it is in water

Question 11Not answered

A wheelbarrow has its load in the middle, the wheel (fulcrum) at the front, and the handles (effort) at the back. What class of lever is it?

1. first class
2. third class
3. second class
4. fourth class, not a standard lever

Question 12Not answered

Sweeping with a broom, holding the top hand still and driving with the lower hand, makes the broom a lever of which class?

1. First class
2. Third class
3. Second class
4. It acts as a pulley instead

Question 13Not answered

An object placed in water will float if

1. it weighs less than one pound in total
2. it is hollow rather than solid inside
3. it displaces a weight of water equal to its own
4. it is made of a material lighter than air

Question 14Not answered

A lever with a mechanical advantage of less than one is useful because it

1. trades force away in exchange for speed and range of movement
2. lets a small effort raise a very heavy load
3. reduces the total work the operator must do
4. eliminates friction at the fulcrum entirely

Question 15Not answered

Compared with a short ramp reaching the same height, a longer ramp requires

1. less force applied over the same distance
2. more force applied over a greater distance
3. the same force applied over a greater distance
4. less force applied over a greater distance

Question 16Not answered

At the bolt, a 1.5 foot wrench receives 40 pounds of applied force at its far end. What torque does this generate?

1. 26.7 pound-feet
2. 41.5 pound-feet
3. 60 pound-feet
4. 38.5 pound-feet

Question 17Not answered

A four-legged table has one leg slightly shorter than the others. What is the most likely structural effect?

1. the table becomes stronger overall
2. all four legs automatically share the load equally regardless of length
3. the shorter leg carries the most weight
4. the load is distributed unevenly, overloading the other three legs

Question 18Not answered

What is the momentum of a 4 kilogram object moving at 5 metres per second?

1. 9 kilogram-metres per second
2. 0.8 kilogram-metres per second
3. 50 kilogram-metres per second
4. 20 kilogram-metres per second

Question 19Not answered

A 2 kilogram ball moving at 6 metres per second has how much momentum?

1. 3 kilogram-metres per second
2. 12 kilogram-metres per second
3. 8 kilogram-metres per second
4. 36 kilogram-metres per second

Question 20Not answered

A 40-tooth gear meshes with a 10-tooth gear. For each full turn of the large gear, the small one turns

1. 4 times
2. once
3. a quarter turn
4. 10 times

Question 21Not answered

Triangles are used throughout trusses and bracing because a triangle

1. cannot change shape unless a side changes length
2. uses less material than any other shape
3. spreads the load equally to all three corners
4. is easier to fabricate than a rectangle

Question 22Not answered

According to Pascal's principle, pressure applied to an enclosed fluid is

1. only transmitted in the direction it was applied
2. transmitted equally in all directions throughout the fluid
3. absorbed completely by the fluid and not transmitted
4. transmitted only to the nearest surface

Question 23Not answered

If a vehicle's speed doubles, its kinetic energy becomes

1. four times as great
2. twice as great
3. half as great
4. eight times as great

Question 24Not answered

A mover applies 500 newtons to a piano but the piano does not move at all. How much work is done on the piano?

1. 500 joules
2. 0 joules
3. 50 joules
4. it cannot be determined

Question 25Not answered

A motor does 1500 joules of work in 5 seconds. What is its power output?

1. 7500 watts
2. 300 watts
3. 3.3 watts
4. 1495 watts