Tag: simple machine

Questions Related to simple machine

The mechanical advantage of each machine is determined by

physics simple machine common machines terms related to machines introduction to simple machines

  1. adding the mechanical advantage for each simple machine

  2. finding the simple machine with the largest mechanical advantage

  3. finding the average mechanical advantage for the simple machines

  4. multiplying the mechanical advantage for each simple machine

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Correct Option: D
Explanation:

The mechanical advantage of each machine is determined by  multiplying the mechanical advantage for each simple machine.
Option D is correct

The mechanical advantage of another oar is $3.00$. If the resistance force of the water is $35.0\ lb$, what is the effort force exerted by the rower?

physics simple machine common machines terms related to machines introduction to simple machines

  1. 11.7 lb

  2. 0.0857 lb

  3. 105 lb

  4. 32.0 lb

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Correct Option: A
Explanation:

The $effort=\dfrac{MA}{load}=\dfrac{35lb}{3}=11.7lb$

In a lifting machine, an effort of $500$ N is to be moved by a distance of $20$ m to raise a load of $10000$ N by a distance of $0.8$ m. Determine the velocity ratio and mechanical advantage?

physics simple machine common machines terms related to machines introduction to simple machines

  1. 10 and 35

  2. 20 and 35

  3. 10 and 25

  4. 25 and 20

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Correct Option: D
Explanation:
Distance moved by effort is 20m,that of load is 0.8m

$VR=\dfrac{{E}{} _{d}}{{L}{} _{d}}$

$VR=\dfrac{20}{0.8}$

$VR=25$

the load is 10,000N and effort=500N

$MA=\dfrac{{load}{} _{d}}{{effort}{} _{d}}$

$MA=\dfrac{10000}{500}$

$MA=20$

In an ideal machine,

physics simple machine common machines terms related to machines introduction to simple machines

  1. Velocity Ratio > Mechanical Advantage

  2. Velocity Ratio =0.5 X Mechanical Advantage

  3. Velocity Ratio < Mechanical Advantage

  4. Velocity Ratio = Mechanical Advantage

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Correct Option: D
Explanation:

For an ideal machine the Velocity ratio is always equal to Machanical advantage.

$VR=MA$

Hence option D is correct

What load will be lifted by an effort of $12$ $N$ if the velocity ratio is $18$ and the efficiency of the machine at this load is 60%?

physics simple machine common machines terms related to machines introduction to simple machines

  1. 1N

  2. .130N

  3. 1.30N

  4. 13N

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Correct Option: B
Explanation:

$\eta=\dfrac{load}{effort*VR}*100$

$load=\eta*effort*VR=0.6*12*18=130N$

In a lifting machine, the efforts required for lifting loads of $20$ N and $30$ N were $5$ N and $6$ N respectively. If the velocity ratio of the machine is $20$, determine efficiencies corresponding to loads of $20 $ N and $30$ N

physics simple machine common machines terms related to machines introduction to simple machines

  1. 25 % and 20%

  2. 35% and 55%

  3. 30% and 50%

  4. 60% and 65%

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Correct Option: A
Explanation:

Let us take first case,


 in which $load=20N , effort =5N ,VR=20$

$Efficiency=\dfrac{load}{VR*effort}*100$

Putting above values, we get

$Efficiency=\dfrac{20}{20*5}*100=20%$

In second case we have.  $load=30N , efoort =6N ,VR=20$

$Efficiency=\dfrac{load}{VR*effort}*100$

Putting values we get,

$Efficiency=\dfrac{30}{20*6}*100=25%$

Hence$ Efficiency=25%,20%$

The mechanical advantage for a pulley system is determined by

physics simple machine common machines terms related to machines introduction to simple machines

  1. counting the number of strands holding the resistance force.

  2. counting the number of strands holding and not holding the resistance force.

  3. adding the radii of the pulleys.

  4. multiplying the radii of the pulleys.

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Correct Option: B

If a machine overcomes a load $L$ and the distance travelled by the load is $L _d$. Similarly, the effort applied in the machine is $E$ and the distance travelled by effort is $E _d$, and $'T'$ is the time taken then velocity ratio can be written as 

physics simple machine common machines terms related to machines introduction to simple machines

  1. $\dfrac{E _d}{L _d}$

  2. $\dfrac{L _d}{E _d}$

  3. $\dfrac{E _d}{\sqrt{L _d}}$

  4. $\dfrac{\sqrt{L _d}}{E _d}$

Show answer
Correct Option: A
Explanation:

The VR is define as ratio of distance travelled by effort:distance travelled by load


$VR=\dfrac{{E}{} _{d}}{{L}{} _{d}}$

option A is correct.

In a lifting machine, an effort of 500 N is to be moved by a distance of 20 m to raise a load of 10,000 N by a distance of 0.8 m. Determine the velocity ratio and mechanical advantage.

physics simple machine common machines terms related to machines introduction to simple machines

  1. 25 and 20

  2. 23 and 22

  3. 20 and 30

  4. 25 and 35

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Correct Option: A
Explanation:
Distance moved by effort is 20m,that of load is 0.8m

$VR=\dfrac{{E}{} _{d}}{{L}{} _{d}}$

$VR=\dfrac{20}{0.8}$

$VR=25$

the load is 10,000N and effort=500N

$MA=\dfrac{{load}{} _{d}}{{effort}{} _{d}}$

$MA=\dfrac{10000}{500}$

$MA=20$

Fill in the blank.
In second order lever, velocity ratio 

physics simple machine common machines terms related to machines introduction to simple machines

  1. is greater than one

  2. is less than one

  3. it may be greater than one or less than one

  4. none of the above

Show answer
Correct Option: A
Explanation:

The VR of second order lever is always grater than 1 because effort arm is always longer than load arm.


$VR=\dfrac{{E}{} _{d}}{{L}{} _{d}},Vr>1$