Tag: physics

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Questions Related to physics

Multiple choice physics force concept of force and its unit force - push or pull forces

A set of unequal and opposite forces is called:

  1. Balanced forces

  2. Unbalanced forces

  3. Equilibrium forces

  4. None
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Unequal and opposite forces do not cancel out each other completely and thus resulting in net force acting in a particular direction. A set of such forces is called a set of unbalanced forces.

Multiple choice physics force concept of force and its unit force - push or pull forces

A number of forces act on a body at the same point and the body does not move. What do you conclude from this?

  1. Body is acted upon by a set of balanced forces.

  2. Body is acted upon by a set of unbalanced forces.

  3. Body is acted upon by a set of unknown forces.

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Balanced forces cancel out the effect of each other. Thus, no net external force acts on the body and hence a body at rest does not move.

Multiple choice physics force concept of force and its unit force - push or pull forces

If the forces on an object are balanced, then the net force is:

  1. Either positive or negative depending on the strength of forces.

  2. Negative

  3. Positive

  4. Zero
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

If the forces on the object are balanced, this means that the individual force cancel out each other resulting in a zero net force acting on the object.

Multiple choice physics force concept of force and its unit force - push or pull forces

Mark the correct statement(s).

  1. When unbalanced forces act on an object at rest, the object will move.

  2. Unbalanced forces are necessary to cause a non-moving object to start moving.

  3. Unbalanced forces produces change in motion (acceleration).

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

Unbalanced forces result in a non-zero net external force acting on a body which produces an acceleration of the body in a particular direction and hence the body at rest starts to move in that direction. Thus unbalanced forces are necessary to cause a non moving object to start moving. Thus option D is correct.

Multiple choice physics force concept of force and its unit force - push or pull forces

You alone can push a roller. But when your friend joins you, the roller moves faster. This is because:

  1. forces in same direction add up.

  2. forces in same direction do not add up.

  3. forces in same direction get subtracted.

  4. forces in same direction remain same.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

When your friend joins you, both of you push the roller in same direction. So, your forces, being applied in same direction, add up to a larger value. Thus the roller moves faster.

Multiple choice physics force concept of force and its unit force - push or pull forces

If force is applied on the body in the direction of motion then

  1. Speed of the body will increase

  2. Speed of the body will decrease

  3. Speed of the body will not change at all

  4. All the options are possible
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

If applied force acts on a body in the direction of motion,the speed of the body will increase.

If the direction of force on the body is opposite to the direction of motion,the speed will decrease.

Multiple choice physics force concept of force and its unit force - push or pull forces

Which of the following pairs of forces will never give resultant force of $2N$

  1. $2N$ and $2N$
  2. $1N$ and $1N$
  3. $1N$ and $3N$

  4. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Because if these two forces Act then it cancelled out because they have the same value. Either it acts in same or opposite direction 
Multiple choice physics force concept of force and its unit force - push or pull forces

A particle is moving along x-axis under the action of a force, $F$ which varies with its postion (x) as $F \propto x^{-1/4}$. The variation of power due to this force with $x$ is

  1. $x^{\dfrac{1}{3}}$
  2. $x^{\dfrac{1}{8}}$
  3. $x^{\dfrac{1}{2}}$
  4. $x^{\dfrac{1}{4}}$
Reveal answer Fill a bubble to check yourself
D Correct answer
Multiple choice physics force concept of force and its unit force - push or pull forces

A rope of mass $ 5 kg$ is moving vertically in vertical position with an upwards force of $100$ $N$ acting at the upper end and a downwords force of $70$$N$ acting at the lower end The tension at midpoint of the rope is

  1. $100 N$
  2. $85 N$
  3. $75 N$
  4. $105 N$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The net force on the rope is 100 N - 70 N = 30 N. The mass is 5 kg, so acceleration a = F_net / m = 30 / 5 = 6 m/s^2 upwards. For the bottom half (mass 2.5 kg), the forces are Tension T and gravity (2.5 * 10 = 25 N). T - 25 = m_half * a = 2.5 * 6 = 15. Thus, T = 40 N. Wait, re-evaluating: The force at the midpoint is the average of the forces at the ends if the rope is uniform and acceleration is constant. (100 + 70) / 2 = 85 N.