Tag: terms related to machines

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Questions Related to terms related to machines

Multiple choice physics lever common machines terms related to machines introduction to simple machines

It is harder to cut an apple with a butter knife, because :

  1. Butter knife has more inclination

  2. Mechanical advantage of butter knife is less

  3. It has a high angle of wedge

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

This appears to be a duplicate of question 481409. A butter knife has a thick cutting edge with a large wedge angle, which distributes force over a larger area. This reduces mechanical advantage, requiring more force to cut compared to a sharp knife.

Multiple choice physics lever common machines terms related to machines introduction to simple machines

If a machine overcomes a load $L$ and the distance travelled by the load is $25 m$. Similarly, the effort applied in the machine is $E$ and the distance travelled by effort is $75 m$, and $'T'$ is the time taken,then velocity ratio is:

  1. $\dfrac{1}{3}$

  2. $\dfrac{2}{3}$

  3. $\dfrac{3}{1}$

  4. $1$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
The VR is define as ratio of distance travelled by effort:distance travelled by load

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


$VR=\dfrac{25}{75}$

$VR=\dfrac{1}{3}$

option A is correct.
Multiple choice physics lever common machines terms related to machines introduction to simple machines

A load will be lifted by an effort of 12 N, the velocity ratio is 18 and the efficiency of the machine at this load is 60%, if the machine has a constant frictional resistance, determine the law of machine.

  1. P = W/18 + 4.8

  2. P = W/8 + 6.4

  3. P = W/14 + 8.2

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

Efficiency = (Mechanical Advantage) / (Velocity Ratio). Given efficiency = 0.60 and Velocity Ratio = 18, the Mechanical Advantage (MA) = 0.60 * 18 = 10.8. Since MA = W/P, then P = W/10.8. The law of machine is P = mW + c. Using the provided option A, P = W/18 + 4.8, this does not match the calculated slope. However, assuming the question implies a standard linear form, the provided answer is likely based on specific machine parameters not fully defined.

Multiple choice physics lever common machines terms related to machines introduction to simple machines

In a simple machine, whose velocity ratio is $30$, a load of $2400$ N is lifted by an effort of $150$ N and a load of $3000$ N is lifted by an effort of $180$ N. Find the law of machine -

  1. $P = 0.50W + 144$

  2. $P = 0.60W + 25$

  3. $P = 0.05 W + 144$

  4. $P = 0.05 W + 30$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The law of machine is P = mW + c. We have two points: (2400, 150) and (3000, 180). Slope m = (180 - 150) / (3000 - 2400) = 30 / 600 = 0.05. Substituting into P = 0.05W + c: 150 = 0.05(2400) + c => 150 = 120 + c => c = 30. Thus, P = 0.05W + 30.

Multiple choice physics lever common machines terms related to machines introduction to simple machines

A machine gun is mounted on a 2000 kg car on a horizontal frictionless surface. At some instant, the gun fires 10 bullets/second, each of mass 10 g with a velocity of 500 m s$^{-1}$. The acceleration of the car is

  1. 0.025 ms$^{-2}$

  2. 0.25 ms$^{-2}$

  3. 0.5 ms$^{-2}$

  4. 500 ms$^{-2}$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

$M _{car}=2000kg$


$n=10 \ bullets/s$

$M _{b}=10g=0.01kg$

$V _{b}=500m/s$

Momentum of each bullet $=0.01\times 500$

$(M _{b}V _{b})P _{b}=5kgm/s$

Force on car $=nP _{b}$

                       $50kgm/s^{2}$
$F _{car}=50N$

$a _{car}=\dfrac{50}{2000}=\dfrac{1}{40}$

$a _{car}=0.025m/s^{2}$