Tag: physics

Questions Related to physics

Fill in the blank.

A rubber balloon _________ when the molecules of air exert force on its walls. 

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

  1. Expands

  2. Contracts

  3. No change in dimension is seen

  4. All of the above 

Show answer
Correct Option: A
Explanation:

Force can bring change in dimension.A rubber balloon expands when the molecules of air exert force on its walls.

Study the impact force when a golfer drives a golf ball $230$ meters down the fairway.

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

  1. The impact force on the golf ball is greatest

  2. The impact force on the club head is greatest

  3. The impact force is the same for both

  4. The impact force has no effect on the club

  5. The impact force has no effect on the ball

Show answer
Correct Option: C
Explanation:

The impact force or impulse is given by $I=F\times t$  

 by Newton's third law both will exert an equal and opposite force on each other and time of impact is also same therefore  impact force (impulse) is same for both.

An object is subjected to a non-zero net force, $F$. Which of the following statements about its motion could not be true?

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

  1. The object will remain at rest

  2. The object has a constant velocity

  3. The object is travelling in a straight-line path with a constant speed

  4. The object is travelling in a circular path with a constant speed

  5. The acceleration of the object is perpendicular to the net force

Show answer
Correct Option: A
Explanation:

Net force on an object is directly proportional to the acceleration of the particle which is the rate of change of velocity.

When a body moves in a uniform circular motion, its velocity keep on changing though its speed is constant.

The amateur boxers, use larger and more padded gloves than professional boxers. The amateur boxers are more protected from injury because:

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

  1. The larger glove exerts a larger impulse on the boxer

  2. The larger glove exerts a larger force on the boxer

  3. The larger glove exerts more energy on the boxer

  4. The larger glove increases time of impact on the boxer

  5. The larger glove increases the power exerted on the boxer

Show answer
Correct Option: D
Explanation:

We have impulse $\vec{I}=\vec{F}\times t=\vec{p} _{2}-\vec{p} _{1}$ 

when a boxer hits another boxer , change in momentum remains constant therefore product of force and time should be constant .we can decrease the force by increasing time of impact so boxer uses larger gloves to increase the time of impact  thus  decreases the force and avoids from injury.

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 seen

  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:

The force can net be seen but we can see the effects of the force. The force is a pull or a push. The effect of forces are like as it causes an object to move, it can change the motion of the body, it can change shape or volume of the body. 

State whether true or false.
When a body is travelling at a constant velocity, the net force on it is infinite.
physics along with motion what forces can do? force and it's unit force and its effects

  1. True

  2. False

Show answer
Correct Option: B
Explanation:

If Body is travelling with constant velocity.

   $V=C$
   $a=0$
$F=0$ (newton second law)


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

Show answer
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

Show answer
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

Show answer
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.

Show answer
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.