Tag: physics

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Multiple choice physics a little effort, lot of work motion in application common machines introduction to simple machines

In an ideal mechanical the output energy is :

  1. more than input energy

  2. equal to input energy

  3. less than input energy

  4. infinite compared to input energy
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Ideal machine. The term ideal machine refers to a hypothetical mechanical system in which energy and power are not lost or dissipated through friction, deformation, wear, or other inefficiencies.The mechanical efficiency of a simple machine is calculated by dividing the actual power output by the ideal power output.

Multiple choice physics a little effort, lot of work motion in application common machines introduction to simple machines

For every turn of a screw jack:

  1. object would be lifted up by the distance between two successive threads

  2. object will be lifted up by half the distance between two successive threads

  3. object will be lifted up by twice the distance between two successive threads

  4. none of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A screw jack converts rotational motion into linear motion. For one full rotation of the handle, the load is lifted by a distance equal to the pitch of the screw, which is the distance between two successive threads.

Multiple choice physics a little effort, lot of work motion in application common machines introduction to simple machines

The law of a certain lifting machine is $P =W/50+ 1.5$. The velocity ratio of the machine is 100. Find the maximum possible mechanical advantage and maximum possible efficiency of the machine

  1. 50 and 50%

  2. 50 and 60%

  3. 60 and 60%

  4. 60 and 50%
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The law of the machine is P = W/50 + 1.5. The maximum mechanical advantage is the reciprocal of the coefficient of W, which is 50. Efficiency is (Mechanical Advantage / Velocity Ratio) * 100, so (50/100) * 100 = 50%.