Tag: force - push or pull

Questions Related to force - push or pull

Two forces of $12 \mathrm { N } \text { and } 8 \mathrm { N }$ acts upon a body. The resultant force on the body has maximum value of

physics forces - vectors and moments concept of force and its unit force - push or pull forces

  1. $4 \mathrm { N }$

  2. $0 \mathrm { N }$

  3. $20 \mathrm { N }$

  4. $8 \mathrm { N }$

Show answer
Correct Option: C
Explanation:

Given,

$|\vec F _1|=12N$
$|\vec F _2|=8N$

The resultant force on the body is 
$|\vec R|=\sqrt{F _1^2+F _2^2+2F _1F _2cos\theta}$

For maximum value, $cos\theta=1$
$|\vec R|=\sqrt{(12)^2+(8)^2+2\times 12\times 8\times 1}$

$|\vec R _{max}|=\sqrt{144+64+24\times 8}$

$|\vec R _{max}|=\sqrt{400}=20N$
The correct option is C.

Fill in the blanks:
The net force is ______ than the individual applied forces.

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

  1. either larger or smaller

  2. always smaller

  3. always greater

  4. always equal

Show answer
Correct Option: A
Explanation:

The net force is either sum or difference of individual applied forces. So, the force is either larger or smaller than individual forces.

In tug of war, if the two teams have equal strength then:

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

  1. the rope will break.

  2. the rope will stay at the same place.

  3. the rope will move towards one of the sides.

  4. the rope will move towards each end alternatively.

Show answer
Correct Option: B
Explanation:

The rope breaks only if the force applied by both the teams is very large. It has nothing to do with the equality of the strength in the teams on the two sides of the rope.
In a tug of war, if the two teams are applying equal force on the rope then the net force acting on the rope is zero and hence the rope stays at the same place.

A set of unequal and opposite forces is called:

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

  1. Balanced forces

  2. Unbalanced forces

  3. Equilibrium forces

  4. None

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Correct Option: B
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.

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

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

  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

Show answer
Correct Option: A
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.

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

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

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

  2. Negative

  3. Positive

  4. Zero

Show answer
Correct Option: D
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.

The strength of force is expressed by?

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

  1. Direction

  2. Magnitude

  3. Both

  4. None

Show answer
Correct Option: B
Explanation:

Force could be larger or smaller than the other.the strength of a force is usually expressed by its magnitude.

Mark the correct statement(s).

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

  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

Show answer
Correct Option: D
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.

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

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

  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.

Show answer
Correct Option: A
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.

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

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

  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

Show answer
Correct Option: A
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.