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

Akhil has to lift a load of 800 N onto a platform of 2 m height. Instead, he pushes the load up a ramp 4 m long. Find the force required to roll the load up the ramp.

  1. 200 N

  2. 600 N

  3. 400 N

  4. 800 N
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Force required to roll the load up the ramp (F) $=\displaystyle \frac{load \times height}{distance}$
$= 800 \displaystyle \times \frac{2}{4} = 400 N$

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

The ratio of the radius of two wheels A and B are in the ratio 3 : 7 respectively and the ratio of their respective axles is 5 : 4. Identify the wheel and axle that has greater mechanical advantage?

  1. A

  2. B

  3. Both have same

  4. Can't say
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The mechanical advantage of a wheel and axle $= \displaystyle \frac{Radius \ of \ wheel}{Radius \ of \ the \ axle}$
$MA _A = \displaystyle \frac{R _1}{r _1} $ and  $MA _B = \displaystyle \frac{R _2}{r _2}$
Given $ r _1  :  r _2  = 5 : 4$
$R _1  :  R _2  = 3  :  7$
$ \displaystyle \frac{MA _A}{MA _B} = \frac{R _1}{r _1} \times \frac{r _2}{R _2}$
$\displaystyle = \frac{3}{5} \times \frac{4}{7} = \frac{12}{35}$
$MA _B >  MA _A$

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

In a wheel-axle arrangement, the radius of wheel is 25 times more than the radius of an axle. Find the mechanical advantage of the machine.

  1. 20

  2. 25

  3. 30

  4. 35
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The mechanical advantage of a wheel and axle $= \displaystyle \frac{Radius  of  wheel}{Radius  of  the  axle}$
Given radius of wheel $=$ 25 $\times$ radius of axle
$MA = \displaystyle \frac{25 \times radius  of  axle}{radius  of  axle} = 25$

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

Which of the following statements in NOT correct?

  1. In a first order lever, the fulcrum is placed between the effort and the load.

  2. The mechanical advantage of a second class levers is greater than 1 as load is situated in between to effort and fulcrum.

  3. An inclined plane in a hospital, helps in pushing a wheel chair easily.

  4. A crow bar is an example of second class level.
Reveal answer Fill a bubble to check yourself
A,B,C Correct answer
Multiple choice physics lever common machines terms related to machines introduction to simple machines

An effort of 20 kgf is applied on a machine through a distance of 80 cm, when a load of 30 kgf moves through a distance of 1 cm. Calculate the velocity ratio of the machine.

  1. 40

  2. 80

  3. 160

  4. 60
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Velocity ratio $= \displaystyle \frac{distance \ of \ the \ effort}{distance \ moved \ by \ the \ load}$
$= \displaystyle \frac{80  cm}{1  cm}= 80$

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

Akhil has to lift a load of 800 N onto a platform of 2 m height. Instead, he pushes the load up a ramp 4 m long. Find the work done by Akhil in lifting the load vertically up.

  1. 800 J

  2. 1600 J

  3. 400 J

  4. 200 J
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The work done by Akhil in lifting the load vertically up $=$ Force $\times$ height
$= 800 \times 2 = 1600 \ J$

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

A nut can be opened by a lever of length $0.25$ m by applying a force of $80$ N. What should be the length of the lever if a force of $32$ N is enough to open the nut?

  1. <span>$625$ m</span>

  2. <span>$1625$ m</span>

  3. <span>$0.625$ m</span>

  4. <span>$6.25$ m</span>
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Using the principle of moments: F1 * L1 = F2 * L2. 80 N * 0.25 m = 32 N * L2. L2 = (80 * 0.25) / 32 = 20 / 32 = 0.625 m.

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

A rubber ball dropped from a height of $20\ m (g = 10\ m/s^{2})$ falls on the roof of an elevator going up at $2\ m/s$. If the collision of the ball with the elevator is elastic, the ball rebounds with a velocity of

  1. $20\ m/s$

  2. $22\ m/s$

  3. $24\ m/s$

  4. $26\ m/s$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Velocity of ball before impact: v = sqrt(2gh) = sqrt(2 * 10 * 20) = 20 m/s (downward). Elevator velocity = 2 m/s (upward). Relative velocity of ball w.r.t elevator = 20 - (-2) = 22 m/s. After elastic collision, it rebounds at 22 m/s relative to the elevator. Absolute velocity = 22 + 2 = 24 m/s.