Dynamics: Master Newton's Laws, Forces, Momentum, and Energy

Question 1

Which of the following is NOT one of Newton's three Laws of Motion?

Accepted Answer

Momentum is conserved in a closed system.

Answer

An object at rest stays at rest, and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force.

Answer

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

Answer

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

Question 2

Which of the following is the unit of momentum?

Accepted Answer

kg m/s

Answer

N s

Answer

J

Answer

W

Question 3

Which of the following is a non-conservative force?

Accepted Answer

Friction

Answer

Gravity

Answer

Tension

Answer

Elastic force

Question 4

Which of the following is not a type of fundamental force?

Accepted Answer

Displacement force

Answer

Gravitational force

Answer

Electrostatic force

Answer

Strong nuclear force

Question 5

According to Newton's second law of motion, the acceleration of an object is directly proportional to the:

Accepted Answer

Net force acting on the object

Answer

Mass of the object

Answer

Velocity of the object

Answer

Displacement of the object

Question 6

What is the momentum of a 50 kg object moving at 10 m/s?

Accepted Answer

500 kg m/s

Answer

5 kg m/s

Answer

50 kg m/s

Answer

5000 kg m/s

Question 7

For an object resting on a flat surface, draw a free body diagram showing all the forces acting on it.

Accepted Answer

A diagram showing both the force of gravity acting vertically downwards and the normal force acting vertically upwards

Answer

A diagram showing only the force of gravity acting vertically downwards

Answer

A diagram showing only the normal force acting vertically upwards

Question 8

A car maintains a constant velocity of 20 m/s. What is the net force acting on the car?

Accepted Answer

0 N

Answer

20 N

Answer

Insufficient information to determine

Answer

Equal to the car's weight

Question 9

Which of the following is not considered a type of force?

Accepted Answer

Momentum

Answer

Contact force

Answer

Field force

Answer

Gravitational force

Question 10

Which of the following quantities is a scalar?

Accepted Answer

Mass

Answer

Velocity

Answer

Acceleration

Answer

Force

Question 11

A car with a mass of 1000 kg is traveling at a speed of 10 m/s. Calculate its momentum.

Accepted Answer

10,000 kg m/s

Answer

100 kg m/s

Answer

1000 kg m/s

Answer

100,000 kg m/s

Question 12

Identify the non-contact force among the following options:

Accepted Answer

Gravity

Answer

Friction

Answer

Tension

Answer

Normal force

Question 13

Which of the following correctly defines the work done by a force on an object?

Accepted Answer

Force multiplied by distance moved in the direction of the force

Answer

Force multiplied by velocity of the object

Answer

Force multiplied by acceleration of the object

Answer

Force multiplied by time for which the force acts

Question 14

In which of the following systems is energy conserved?

Accepted Answer

A swinging pendulum

Answer

A car braking to a stop

Answer

A ball bouncing off a wall

Answer

A firework exploding

Question 15

What is the acceleration of an object due to gravity on Earth (approximately)?

Accepted Answer

9.81 m/s²

Answer

10 m/s²

Answer

9.18 m/s²

Answer

10.2 m/s²

Question 16

Which of the following is a vector quantity?

Accepted Answer

Force

Answer

Mass

Answer

Temperature

Answer

Time

Question 17

Which of the following is the correct definition of power?

Accepted Answer

Work done per unit time

Answer

Force applied per unit time

Answer

Energy stored per unit time

Answer

Momentum per unit time

Question 18

Which of the following is not a type of friction?

Accepted Answer

Viscous friction

Answer

Static friction

Answer

Sliding friction

Answer

Rolling friction

Question 19

According to Newton's second law of motion, the acceleration of an object is:

Accepted Answer

Inversely proportional to the mass and directly proportional to the net force

Answer

Directly proportional to the mass and inversely proportional to the net force

Answer

Equal to the net force acting on the object

Answer

Independent of the mass and the net force

Question 20

Which of the following is the SI unit of force?

Accepted Answer

Newton

Answer

Joule

Answer

Watt

Answer

Pascal

Question 21

Which of the following is a vector quantity?

Accepted Answer

Displacement

Answer

Speed

Answer

Mass

Answer

Temperature

Question 22

Which factor does not affect the period of a simple pendulum?

Accepted Answer

Amplitude of the swing

Answer

Length of the pendulum

Answer

Mass of the pendulum bob

Answer

Strength of gravitational field

Question 23

An object is rotating around a fixed axis. Describe the relationship between its angular acceleration, moment of inertia about the axis, and the applied torque.

Accepted Answer

Angular acceleration is directly proportional to torque and inversely proportional to moment of inertia.

Answer

Angular acceleration is directly proportional to moment of inertia and inversely proportional to torque.

Answer

Angular acceleration is inversely proportional to both torque and moment of inertia.

Answer

Angular acceleration is directly proportional to the square of torque and inversely proportional to the square of moment of inertia.

Question 24

A car of mass 1000 kg is moving at a velocity of 20 m/s. Calculate the kinetic energy of the car.

Accepted Answer

1000 kJ

Answer

10 kJ

Answer

100 kJ

Answer

10000 kJ

Question 25

Two blocks of masses 5 kg and 10 kg are connected by a string and placed on a frictionless surface. A force of 15 N is applied to the 10 kg block. Calculate the acceleration of the system.

Accepted Answer

3 m/s^2

Answer

1.5 m/s^2

Answer

6 m/s^2

Answer

12 m/s^2

Question 26

Which of the following is a vector quantity?

Accepted Answer

Velocity

Answer

Mass

Answer

Temperature

Answer

Energy

Question 27

Explain the relationship between impulse and momentum. Provide a practical example to demonstrate its significance in real-life situations.

Accepted Answer

Impulse is the change in momentum that occurs over a specific time interval.

Answer

Impulse is the force applied to an object, and it is always equal to the momentum.

Answer

Momentum is the rate at which impulse changes over time.

Answer

Impulse is a measure of the strength of a force, independent of its duration.

Question 28

A car of mass 1000 kg is traveling at a constant velocity of 20 m/s. Determine the net force acting on the car.

Accepted Answer

0 N

Answer

4000 N

Answer

2000 N

Answer

1000 N

Question 29

A car of mass 1000 kg is traveling at a speed of 20 m/s. What is its kinetic energy?

Accepted Answer

100 kJ

Answer

50 kJ

Answer

200 kJ

Question 30

Which of the following is NOT considered a force in physics?

Accepted Answer

Energy

Answer

Tension

Answer

Gravity

Answer

Friction

Question 31

In a closed system, which of the following quantities remains constant?

Accepted Answer

Momentum

Answer

Velocity

Answer

Kinetic energy

Answer

Force

Question 32

Which factor significantly affects the strength of friction?

Accepted Answer

Normal force

Answer

Temperature

Answer

Velocity

Answer

Acceleration

Question 33

What is the SI unit of momentum?

Accepted Answer

kg m/s

Answer

J

Answer

N

Question 34

Which of the following is NOT a type of force?

Accepted Answer

Velocity

Answer

Tension

Answer

Friction

Answer

Gravity

Question 35

A 10 kg box is pushed with a force of 20 N. Calculate the acceleration of the box?

Accepted Answer

2 m/s²

Answer

0.5 m/s²

Answer

20 m/s²

Answer

10 m/s²

Question 36

Which of the following is NOT a type of energy?

Accepted Answer

Speed

Answer

Thermal energy

Answer

Potential energy

Answer

Kinetic energy

Question 37

At the highest point of its trajectory, a ball thrown vertically upwards has

Accepted Answer

Zero kinetic energy and maximum potential energy

Answer

Zero potential energy and maximum kinetic energy

Answer

Both kinetic and potential energy are zero

Question 38

The moment of inertia of a body is determined by its

Accepted Answer

Mass and distribution of mass

Answer

Size only

Answer

Mass only

Answer

Shape only

Question 39

Which of the following is a scalar quantity?

Accepted Answer

Speed

Answer

Force

Answer

Velocity

Answer

Acceleration

Question 40

A car of mass 1000 kg maintains a constant velocity of 20 m/s on a straight road. What is the net force acting on the car?

Accepted Answer

0 N

Answer

1000 N

Answer

4000 N

Answer

2000 N

Question 41

Two objects of masses m1 and m2 connected by a light, inextensible string are placed on a horizontal frictionless surface. A constant force F is applied to object m1. What is the acceleration of the two-object system?

Accepted Answer

F/(m1 + m2)

Answer

F/m1

Answer

2F/(m1 + m2)

Answer

F/m2

Question 42

A particle moves in a circular path of radius r with a constant tangential speed v. What is the centripetal force acting on the particle?

Accepted Answer

mv^2/r

Answer

mv^2

Answer

rv^2/2

Answer

mr^2/v^2

Question 43

A 5 kg object has a velocity of 10 m/s. What is the kinetic energy of the object?

Accepted Answer

250 J

Answer

100 J

Answer

500 J

Question 44

Two objects, one of mass 1 kg and the other of mass 2 kg, move with the same velocity. How does the momentum of the heavier object compare to that of the lighter object?

Accepted Answer

Twice that of the lighter object

Answer

Equal to that of the lighter object

Answer

Half that of the lighter object

Question 45

In a perfectly elastic collision between two objects, what happens to the total momentum of the system?

Accepted Answer

Is conserved

Answer

Is doubled

Answer

Is lost

Answer

Is halved

Question 46

Which of the following is the correct SI unit of force?

Accepted Answer

Newton (N)

Answer

Joule (J)

Answer

Pascal (Pa)

Answer

Watt (W)

Question 47

Which of Newton's laws of motion states that an object at rest will remain at rest unless acted upon by an unbalanced force?

Accepted Answer

First law

Answer

Second law

Answer

Law of universal gravitation

Answer

Third law

Question 48

Which of the following is a scalar quantity?

Accepted Answer

Temperature

Answer

Velocity

Answer

Momentum

Answer

Force

Question 49

A 2 kg object is placed at rest on a frictionless surface. A force of 10 N is applied to the object for 2 seconds. What is the object's final velocity?

Accepted Answer

10 m/s

Answer

20 m/s

Answer

15 m/s

Answer

5 m/s

Question 50

A car of mass 1000 kg accelerates uniformly from rest to 20 m/s in 10 seconds. What is the net force acting on the car?

Accepted Answer

2000 N

Answer

1000 N

Answer

10000 N

Answer

5000 N

Question 51

A book rests on a table. Which of the following statements is true about the forces acting on the book?

Accepted Answer

The normal force from the table and the weight of the book are equal in magnitude and opposite in direction.

Answer

The normal force from the table is greater than the weight of the book.

Question 52

A 5 kg object is moving with a velocity of 10 m/s. What is its kinetic energy?

Accepted Answer

250 J

Answer

125 J

Answer

50 J

Answer

500 J

Question 53

A ball is thrown vertically upwards. Neglecting air resistance, which of the following statements is true about the ball's acceleration at its highest point?

Accepted Answer

The acceleration is constant and equal to the acceleration due to gravity.

Answer

The acceleration is maximum.

Answer

The acceleration is zero.

Question 54

A force of 10 N is applied to a 2 kg object over a distance of 5 meters. What is the work done on the object?

Accepted Answer

50 J

Answer

20 J

Answer

10 J

Question 55

A 0.5 kg ball moving at 4 m/s collides head-on with a stationary 0.5 kg ball. If the collision is perfectly elastic, what are the velocities of the two balls after the collision?

Accepted Answer

First ball: 0 m/s, Second ball: 4 m/s

Answer

First ball: 1 m/s, Second ball: 3 m/s

Answer

First ball: 2 m/s, Second ball: 2 m/s

Answer

First ball: 4 m/s, Second ball: 0 m/s

Question 56

A car is traveling at a constant speed around a circular track. Which of the following statements is true?

Accepted Answer

The car is accelerating because its direction is changing.

Answer

The car is not accelerating because it is moving in a circle.

Answer

The car is not accelerating because its speed is constant.

Question 57

A 10 kg object is placed on a frictionless incline that makes an angle of 30° with the horizontal. What is the component of the object's weight acting parallel to the incline?

Accepted Answer

49 N

Answer

85 N

Answer

0 N

Answer

98 N

Question 58

A force-time graph shows a constant force of 5 N acting on an object for 4 seconds. What is the impulse experienced by the object?

Accepted Answer

20 Ns

Answer

40 Ns

Answer

5 Ns

Answer

10 Ns