Tag: physics

Questions Related to physics

If a nail requires 3 N force to insert into wood, then the value of force required to insert a screw into wood will be:

physics common machines kinds of simple machines inclined plane, wedge, screw and wheel and axle types of simple machines

  1. Less than 3N

  2. Greater than 3N

  3. 3N

  4. Can't say

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Correct Option: A
Explanation:

A screw is preferred over a nail to insert into wood because it requires lesser force to insert. Therefore the value of force required to insert a screw in the given question is less than 3 N.

A door knob is an example of screw.

physics common machines kinds of simple machines inclined plane, wedge, screw and wheel and axle types of simple machines

  1. True

  2. False

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Correct Option: B
Explanation:

A door knob is an example of simple machine.

Gang plank is an example of inclined plane.

physics common machines kinds of simple machines inclined plane, wedge, screw and wheel and axle types of simple machines

  1. True

  2. False

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Correct Option: A
Explanation:

Gangplank is a flat surface  whose end points are at different heights. So it is an example of inclined plane.

_________ is used to separate two objects into pieces.

physics common machines kinds of simple machines inclined plane, wedge, screw and wheel and axle types of simple machines

  1. Screw

  2. Wedge

  3. Lever

  4. Pulley

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Correct Option: B
Explanation:

A Wedge is a triangular shaped tool ,and is a portable inclined plane. It can be used to separate two objects or portion of objects.

A crow bar is used for tearing a part a piece of wood.

physics common machines kinds of simple machines inclined plane, wedge, screw and wheel and axle types of simple machines

  1. True

  2. False

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Correct Option: B
Explanation:

A crowbar also called a wrecking bar is commonly used to open a nailed wooden crates or pry apart boards.

The helical threading of a screw :

physics common machines kinds of simple machines inclined plane, wedge, screw and wheel and axle types of simple machines

  1. increases the mechanical advantage

  2. helps to gain less inclination

  3. holds the wood more firmly than a screw

  4. all of the above

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Correct Option: D
Explanation:
 A small torque applied to a screw  can exert a large axial force on a mass. Therefore, a threaded  component is said to produce a Mechanical Advantage.

(a) Helical threading increases the mechanical advantage.
(b) Also provide less inclination whenever heavy load  act on it.
(c) Helical threading means increasing pitch so it holds wood more firmly than a screw.

A wedge is:

physics common machines kinds of simple machines inclined plane, wedge, screw and wheel and axle types of simple machines

  1. a first order lever

  2. a wheel-and-axle

  3. two inclined planes put together

  4. none of the above

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Correct Option: C
Explanation:

A wedge can be made by putting two inclined plane together .

A screw is preferred over a nail to insert into wood because :

physics common machines kinds of simple machines inclined plane, wedge, screw and wheel and axle types of simple machines

  1. Screw holds more firmly than a nail.

  2. Less force is needed to insert a screw.

  3. Tip of a screw has more area of contact than nail.

  4. Fulcrum of the screw is at its head.

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Correct Option: A,B,D
Explanation:

(a) Screw has thread like grip on it so it holds more firmly than a nail.

(b) You have apply  to torque to insert screw which require less force on the other hand nail require huge impulse to insert.
(c) Tip of both has approximately equal area.
(d) Fulcrum is a pivot around a lever turns ,or something that plays a central role. screw has it at its head.

State true or false.
The more gradual the slope of an inclined plane, then more effort is required to push a load up.

physics common machines kinds of simple machines inclined plane, wedge, screw and wheel and axle types of simple machines

  1. True

  2. False

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Correct Option: A
Explanation:

As slope increases component of weight along inclined plane increases so more effort required to push a load up.

A car develops a force of 400 N and climbs up a vertical distance of 250 m. If the length of the road covered by the car is 5 km, then find the fractional change in load due to the car for the force developed.

physics common machines kinds of simple machines inclined plane, wedge, screw and wheel and axle types of simple machines

  1. 19

  2. 20

  3. 21

  4. 22

Show answer
Correct Option: A
Explanation:

$ MA = \displaystyle \frac{L _{car}}{E _{car}} = \frac{EA}{LA}$
$\displaystyle \frac{L _{car}}{400} = \frac{5000}{250}$
$L _{car} = 8000 N$
Fractional change
$= \displaystyle \frac{L _{car}-E}{E}$
$= \displaystyle \frac{8000 - 400}{400}$
$= \displaystyle \frac{7600}{400}$
$=19$