Which of the following is an example of a wedge?
- A.A crowbar
- B.An axe
- C.A pulley block
- D.A steering wheel
Correct answer
Explanation
The correct answer is B, an axe. A wedge is two inclined planes joined back to back, and an axe, a knife, a chisel and a nail all work on that principle: a force applied at the blunt end is turned into a much larger sideways force at the sharp edge, and the thinner and longer the wedge, the greater its mechanical advantage. Option A is wrong because a crowbar is a lever of the first class, used with a fulcrum close to the load. Option C is wrong because a pulley block belongs to the family of pulleys, in which a rope passes over grooved wheels. Option D is wrong because a steering wheel is an example of the wheel and axle, whose velocity ratio is the radius of the wheel divided by the radius of the axle.
Read the full article: Simple Machines: Levers, Pulleys, Formulas and PYQs
Practice Questions
View allThe effort applied to move a load is 15 units and the mechanical advantage is observed to be 3. Find the load.
- A.5 units
- B.3 units
- C.15 units
- D.45 units
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Mechanical advantage is defined as the load divided by the effort, so the load is the mechanical advantage multiplied by the effort, that is three multiplied by fifteen, which gives forty-five units.
Read the full explanation →Find the efficiency of a pulley system which has a mechanical advantage of 2.5 and where the load lifts by 2.5 metres on pulling the rope by 10 m.
- A.62.50%
- B.25.00%
- C.40.00%
- D.100.00%
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The velocity ratio is the distance moved by the effort divided by the distance moved by the load, that is ten divided by two point five, which is four.
Read the full explanation →The velocity ratio of a simple machine is the ratio of distance travelled by the ________ to the distance travelled by the ________ in the machine.
- A.load; load
- B.effort; load
- C.load; effort
- D.effort; effort
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Velocity ratio is defined as the distance moved by the effort divided by the distance moved by the load in the same interval of time, and because it depends only on the design of the machine it does not change with friction, unlike the mechanical advantage.
Read the full explanation →Which of the following mechanical devices efficiently distributes or multiplies loads with little effort?
- A.Gears
- B.Lever
- C.Shafts
- D.Bearings
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A lever is a rigid bar turning about a fulcrum, and by the principle of moments the load multiplied by the load arm equals the effort multiplied by the effort arm, so a long effort arm lets a small effort balance a large load; this is the simplest way of…
Read the full explanation →A wheelbarrow is an example of which class of lever?
- A.First class
- B.Second class
- C.Third class
- D.It is not a lever
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In a wheelbarrow the wheel acts as the fulcrum, the load sits in the tray between the wheel and the hands, and the effort is applied at the handles, which is the arrangement of a second class lever; because the effort arm is always longer than the load arm, its…
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