Forces

Question 1

What is a force?

Answer 1

A force is a push or pull acting upon an object due to its interaction with another object.

Question 2

What is the unit of force?

Answer 2

The unit of force is the Newton (N).

Question 3

What is Newton’s First Law of Motion?

Answer 3

An object will remain at rest or in uniform motion unless acted upon by a net external force.

Question 4

What is Newton’s Second Law of Motion?

Answer 4

The acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass (F = ma)

Question 5

What is Newton’s Third Law of Motion?

Answer 5

For every action, there is an equal and opposite reaction.

Question 6

What is friction?

Answer 6

Friction is a force that opposes the motion of an object, caused by the contact between surfaces.

Question 7

What is the difference between static and kinetic friction?

Answer 7

Static friction acts on an object at rest, while kinetic friction acts on an object in motion.

Question 8

What is gravitational force?

Answer 8

Gravitational force is the attractive force between two masses, such as the Earth and an object.

Question 9

How does mass affect gravitational force?

Answer 9

The greater the mass of an object, the stronger the gravitational force acting on it.

Question 10

What is weight?

Answer 10

Weight is the force exerted by gravity on an object, calculated using the formula: Weight (W) = mass (m) × gravitational field strength (g).

Question 11

What is a free body diagram?

Answer 11

A free body diagram is a graphical representation showing all the forces acting on an object.

Question 12

What is tension?

Answer 12

Tension is the pulling force transmitted along a rope, string, or cable when it is pulled tight by forces acting from opposite ends.

Question 13

What is air resistance?

Answer 13

Air resistance is a type of friction that acts against the motion of an object moving through the air.

Question 14

What factors affect the size of air resistance?

Answer 14

The size of air resistance is affected by the speed of the object, its shape, and its surface area.

Question 15

What is resultant force?

Answer 15

Resultant force is the single force that represents the combined effect of all the forces acting on an object.

Question 16

What is the formula for calculating acceleration?

Answer 16

Acceleration (a) = Change in velocity (Δv) / Time taken (t).

Question 17

What is the role of a contact force?

Answer 17

Contact forces occur when two objects are physically touching, such as friction, tension, and normal force.

Question 18

What is normal force?

Answer 18

Normal force is the perpendicular force exerted by a surface on an object in contact with it.

Question 19

What happens to an object when the resultant force is zero?

Answer 19

If the resultant force is zero, the object remains at rest or continues to move at a constant velocity.

Question 20

What is a scalar quantity?

Answer 20

A scalar quantity has only magnitude (size), such as mass or temperature, without direction.

Question 21

What is a vector quantity?

Answer 21

A vector quantity has both magnitude and direction, such as force, velocity, and displacement.

Question 22

What is the principle of moments?

Answer 22

For an object to be in equilibrium, the sum of clockwise moments about a pivot must equal the sum of counterclockwise moments.

Question 23

How do you calculate the moment of a force?

Answer 23

Moment (M) = Force (F) × Distance from pivot (d).

Question 24

What is gravitational field strength?

Answer 24

Gravitational field strength (g) is the force of gravity acting on a unit mass at a point in a gravitational field, measured in N/kg.

Question 25

What is tension in a rope?

Answer 25

Tension is the force transmitted through a rope or string when it is pulled tight by forces acting at either end.

Question 26

What is the difference between balanced and unbalanced forces?

Answer 26

Balanced forces result in no change in motion, while unbalanced forces cause an object to accelerate or change direction.

Question 27

What is terminal velocity?

Answer 27

Terminal velocity is the constant speed an object reaches when the force of gravity is balanced by air resistance.

Question 28

What is drag force?

Answer 28

Drag force is a resistance force caused by the motion of a body through a fluid (liquid or gas).

Question 29

What is the equation for calculating weight?

Answer 29

Weight (W) = mass (m) × gravitational field strength (g), where g is approximately 9.81 N/kg on Earth.

Question 30

What is inertia?

Answer 30

Inertia is the tendency of an object to resist changes in its state of motion, dependent on its mass.

Question 31

What is the definition of centripetal force?

Answer 31

Centripetal force is the force directed towards the center of a circular path that keeps an object moving in that circle.

Question 32

How does increasing mass affect acceleration, according to Newton's Second Law?

Answer 32

increasing mass results in a decrease in acceleration if the net force remains constant (F = ma).

Question 33

What is the difference between mass and weight?

Answer 33

Mass is the amount of matter in an object (measured in kg), while weight is the gravitational force acting on that mass (measured in N).

Question 34

What is the role of the normal force on an inclined plane?

Answer 34

The normal force acts perpendicular to the surface and can be less than the object's weight on an inclined plane.

Question 35

What does Hooke's Law state?

Answer 35

Hooke's Law states that the force needed to extend or compress a spring is directly proportional to the distance it is stretched or compressed (F = kx).

Question 36

What is a conservative force?

Answer 36

A conservative force is a force that does work on an object without changing the total mechanical energy (e.g., gravitational force).

Question 37

What happens to an object's motion if the forces acting on it are balanced?

Answer 37

The object will either remain at rest or continue moving with constant velocity.

Question 38

What is the role of gravitational potential energy in a system?

Answer 38

Gravitational potential energy is the energy stored in an object due to its height in a gravitational field, calculated by the formula: PE = mgh.

Question 39

What is the equation of motion relating distance, initial velocity, time, and acceleration?

Answer 39

The equation is: 𝑠 = 𝑢 𝑡 + 1 2 𝑎 𝑡 2 s=ut+ 2 1 ​ at 2 , where 𝑠 s is distance, 𝑢 u is initial velocity, 𝑎 a is acceleration, and 𝑡 t is time.

Question 40

What is the impact of surface area on air resistance?

Answer 40

A larger surface area increases air resistance, slowing down the object more compared to an object with a smaller surface area.