Tag: what forces can do?

Questions Related to what forces can do?

Force is an external effect in the form of a push or pull, which ..................

physics along with motion what forces can do? force and it's unit force and its effects

  1. Produces or tries to produce motion in a body at rest

  2. Stops or tries to stop a moving body

  3. Changes or tries to change the direction of motion of the body

  4. None of these

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Correct Option: A,B,C
Explanation:

When force is applied in the direction of motion it increases velocity,

when applied opposite to the direction of motion it will try to reduce the velocity.
when force is applied at any angle with velocity of object, it will try to give a component in that direction where force is applied hence direction or magnitude of net velocity is changed.
When force is applied to any body, an acceleration is generated in that direction where force is applied.

You are on a frictionless horizontal plane. How can you get off if no horizontal force is exerted by pushing against the surface?

physics along with motion what forces can do? force and it's unit force and its effects

  1. By jumping

  2. By splitting or sneezing

  3. By rolling your body on the surface

  4. By running on the plane

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Correct Option: B
Explanation:

While splitting or sneezing you will exhale things out with some momentum by applying force on it and in return you will experience a force in the opposite direction according to the $Newton's\quad Third\quad Law\quad of\quad Motion$.So, in this way you will aquire a velocity on a frictionless surface and you will be able to get off it.

What causes a moving body to resist a change in its state of motion?

physics along with motion what forces can do? force and it's unit force and its effects

  1. Its acceleration

  2. Its speed

  3. Its inertia

  4. Its weight

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Correct Option: C
Explanation:

The property of a body by virtue of which it resists any change in its state of rest or of motion in a straight line on its own is called its inertia.

A rider on horse falls back when horse starts running all of a sudden because

physics along with motion what forces can do? force and it's unit force and its effects

  1. Rider is taken back

  2. Rider is suddenly afraid of falling

  3. Inertia of rest keeps the upper part of body at rest while lower part of the body moves forward with the horse.

  4. Inertia of motion keeps the upper part of body at rest while lower part of the body moves forward with the horse.

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Correct Option: C
Explanation:

A rider on horse falls back when horse starts running, all of a sudden because the rider is in state of rest initially and later inertia of rest keeps the upper part of body at rest while lower part of the body moves forward with horse.

If a body is moving with a constant speed along a straight line; then in order to change its direction of motion, an external force has to be applied in a direction normal to the direction of motion.

physics along with motion what forces can do? force and it's unit force and its effects

  1. True

  2. False

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Correct Option: A
Explanation:

Newton's First law of motion - "Every body continues to be in its state of rest or of uniform motion in a straight line unless compelled by some external force to act otherwise". 

According to Newton's First law of motion, statement is true, an external force has to be applied in a direction normal to the direction of motion to change its direction of motion

Which of the statements about force are true?

physics along with motion what forces can do? force and it's unit force and its effects

  1. It can be seed

  2. It causes an object to move

  3. It is pull or a push

  4. It can change the motion of an object

Show answer
Correct Option: B,C,D
Explanation:

Force cannot be seen as it is a push or pull. But it causes an object to or can also change the motion of an object.

Three forces are acting on a body in which of following option (s) can the body be in equilibrium?

physics along with motion what forces can do? force and it's unit force and its effects

  1. $2N, 4N, 5N$

  2. $1N, 2N, 4N$

  3. $3N, 3N, 7N$

  4. $5N, 2N, 1N$

Show answer
Correct Option: A
Explanation:

Three force are in equilibrium if 

1) All forces are in a plane 
2) Sum of two small forces is less than bigger force.
This condition is satisfy by option A
Answerer A

A ball of mass 250 g  moving  with a speed of  hits a wall normally . it rebounds with the same speed . If the two were in contact for , the average force exerted by the wall on the ball is 

physics along with motion what forces can do? force and it's unit force and its effects

  1. $4 \times {10^{ - 3}}N$

  2. $2 \times {10^{ - 3}}N$

  3. ${10^{ - 3}}N$

  4. ${10^{ - 2}}N$

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Correct Option: B

 A force of $15 N$ increases the length ofa by $1 \mathrm { mm }$. The additional force require increase the length by $2.5 \mathrm { mm }$ in N is 

physics along with motion what forces can do? force and it's unit force and its effects

  1. $2.25$

  2. $22.5$

  3. $37.5$

  4. $3.75$

Show answer
Correct Option: B
Explanation:

We know,

$Y=\dfrac{FL}{A\Delta L}$

For a wire, A,L,Y are constant.

$\dfrac{F}{\Delta L}=$constant

Let extra Force needed be $ F$,

$\dfrac{15}{1}=\dfrac{F+15}{2.5}$

$F+15=2.5\times 15$

$F=1.5\times 15=22.5$

Option $\textbf B$ is the correct answer

The force between two identical bar magnets whose centers are r meter apart is $2.8$N when their axis are in the same line. If the separation is increased to $2r$ meters, the force between them is reduced to

physics along with motion what forces can do? force and it's unit force and its effects

  1. $2.4N$

  2. $1.2$N

  3. $0.7$N

  4. $0.175$N

Show answer
Correct Option: C