Unit 2: Force and Translational Dynamics

Question 1

What is Newton’s First Law of Motion?

Answer 1

An object at rest stays at rest and an object in motion stays in motion unless acted upon by a net external force.

Question 2

What is the formula for force?

Answer 2

Force (F) is given by F = m * a, where m is mass and a is acceleration.

Question 3

True or False: Weight is the force of gravity acting on an object.

Answer 3

True.

Question 4

What is the equation for weight?

Answer 4

Weight (W) is given by W = m * g, where g is the acceleration due to gravity (approximately 9.81 m/s²).

Question 5

Fill in the blank: The net force acting on an object is equal to its mass times its __________.

Answer 5

acceleration.

Question 6

What does the term ‘friction’ refer to?

Answer 6

Friction is the force that opposes the relative motion of two surfaces in contact.

Question 7

What is the coefficient of friction?

Answer 7

The coefficient of friction (μ) is a dimensionless scalar value that represents the frictional force between two bodies.

Question 8

What are the two types of friction?

Answer 8

Static friction and kinetic friction.

Question 9

What is the formula for static friction?

Answer 9

Static friction (f_s) can be calculated as f_s ≤ μ_s * N, where N is the normal force.

Question 10

What is the formula for kinetic friction?

Answer 10

Kinetic friction (f_k) is given by f_k = μ_k * N.

Question 11

True or False: The acceleration of an object is directly proportional to the net force acting on it.

Answer 11

True.

Question 12

What is the equation for acceleration?

Answer 12

Acceleration (a) is given by a = F_net / m, where F_net is the net force.

Question 13

Define ‘mass’.

Answer 13

Mass is a measure of the amount of matter in an object, usually measured in kilograms.

Question 14

What is ‘inertia’?

Answer 14

Inertia is the tendency of an object to resist changes in its state of motion.

Question 15

What is Newton’s Second Law of Motion?

Answer 15

The acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass.

Question 16

If a 5 kg object experiences a net force of 15 N, what is its acceleration?

Answer 16

The acceleration is 3 m/s² (using a = F/m).

Question 17

What is the formula for momentum?

Answer 17

Momentum (p) is given by p = m * v, where v is velocity.

Question 18

True or False: Momentum is conserved in a closed system.

Answer 18

True.

Question 19

What is the principle of conservation of momentum?

Answer 19

In a closed system, the total momentum before an event is equal to the total momentum after the event.

Question 20

Define ‘net force’.

Answer 20

Net force is the vector sum of all the forces acting on an object.

Question 21

What is the unit of force in the SI system?

Answer 21

The unit of force is the newton (N).

Question 22

What does ‘N’ stand for in the context of force?

Answer 22

N stands for newton, which is the unit of force.

Question 23

Fill in the blank: The force of gravity is often referred to as __________.

Answer 23

weight.

Question 24

What is the value of gravitational acceleration (g) near the surface of the Earth?

Answer 24

Approximately 9.81 m/s².

Question 25

What is the effect of air resistance on falling objects?

Answer 25

Air resistance opposes the motion of falling objects, reducing their acceleration.

Question 26

What is terminal velocity?

Answer 26

Terminal velocity is the constant speed that a freely falling object eventually reaches when the resistance of the medium prevents further acceleration.

Question 27

What is Newton's Third Law of Motion?

Answer 27

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

Question 28

True or False: Action and reaction forces act on the same object.

Answer 28

False.

Question 29

What is the formula for calculating the normal force (N) on a flat surface?

Answer 29

N = m * g, assuming no vertical acceleration.

Question 30

What is the difference between mass and weight?

Answer 30

Mass is the amount of matter in an object, while weight is the gravitational force acting on that mass.

Question 31

Fill in the blank: The force exerted by a surface to support the weight of an object is called __________.

Answer 31

normal force.

Question 32

What is the role of friction in motion?

Answer 32

Friction opposes the relative motion between surfaces in contact.

Question 33

What determines the amount of kinetic friction between two surfaces?

Answer 33

The coefficient of kinetic friction and the normal force.

Question 34

True or False: Increasing the surface area in contact will always increase friction.

Answer 34

False.

Question 35

What is the formula for calculating the net force in a frictional scenario?

Answer 35

F_net = F_applied - F_friction.

Question 36

What is the difference between static and kinetic friction?

Answer 36

Static friction occurs when an object is not moving, while kinetic friction occurs when it is sliding.

Question 37

What is an example of an action-reaction pair?

Answer 37

A person pushing against a wall and the wall pushing back against the person.

Question 38

What is the equation for work done by a force?

Answer 38

Work (W) is given by W = F * d * cos(θ), where d is the displacement and θ is the angle between force and displacement.

Question 39

Define 'energy'.

Answer 39

Energy is the capacity to do work.

Question 40

What is kinetic energy and its formula?

Answer 40

Kinetic energy (KE) is the energy of an object due to its motion, given by KE = 1/2 * m * v².

Question 41

What is potential energy and its formula?

Answer 41

Potential energy (PE) is the stored energy of an object due to its position, given by PE = m * g * h.

Question 42

True or False: Energy is conserved in an isolated system.

Answer 42

True.

Question 43

What is the law of conservation of energy?

Answer 43

Energy cannot be created or destroyed, only transformed from one form to another.

Question 44

What is a free-body diagram?

Answer 44

A free-body diagram is a graphical representation used to visualize the forces acting on an object.

Question 45

What does the area under a force vs. time graph represent?

Answer 45

The area under a force vs. time graph represents impulse.

Question 46

What is impulse and its formula?

Answer 46

Impulse (J) is the change in momentum, given by J = Δp = F * Δt.

Question 47

True or False: Impulse is equal to the change in momentum.

Answer 47

True.

Question 48

What is the relationship between impulse and momentum?

Answer 48

Impulse is equal to the change in momentum of an object.

Question 49

What is the significance of the slope of a velocity vs. time graph?

Answer 49

The slope of a velocity vs. time graph represents acceleration.

Question 50

What is the formula for gravitational potential energy near Earth's surface?

Answer 50

PE = m * g * h.

Question 51

Fill in the blank: The acceleration due to gravity is __________.

Answer 51

9.81 m/s².

Question 52

What is the effect of mass on gravitational force?

Answer 52

Gravitational force increases with mass.

Question 53

What is the equation for the gravitational force between two masses?

Answer 53

F_gravity = G * (m₁ * m₂) / r², where G is the gravitational constant.

Question 54

Define 'net acceleration'.

Answer 54

Net acceleration is the total acceleration of an object considering all acting forces.

Question 55

What is the effect of unbalanced forces on an object?

Answer 55

Unbalanced forces cause an object to accelerate.

Question 56

What is the difference between contact forces and non-contact forces?

Answer 56

Contact forces require physical contact between objects, while non-contact forces act at a distance.

Question 57

What is an example of a non-contact force?

Answer 57

Gravity.

Question 58

What is the relationship between force, mass, and acceleration?

Answer 58

Force is the product of mass and acceleration (F = m * a).

Question 59

True or False: The greater the mass of an object, the greater the force needed to accelerate it.

Answer 59

True.

Question 60

What is the role of the normal force in vertical motion?

Answer 60

The normal force acts perpendicular to the surface and balances the weight of the object.