Newton's Laws of Motion: Multiple Choice Questions Part I

Which of the following best describes inertia?

• A force that keeps an object in motion indefinitely regardless of external influences

• The tendency of an object to resist any change in its state of motion

• The primary reason friction always acts on moving objects to slow them down

• The ability of an object to create motion without a net applied force

A book rests on a horizontal table. Which force prevents it from falling through the table?

• Weight acting downward due to gravitational attraction

• Gravitational pull that keeps the book near Earth’s surface at all times

• Normal force exerted upward by the table on the book

• Frictional force that arises from microscopic roughness between surfaces

When a jeepney stops suddenly, passengers lurch forward. This best illustrates—

• Newton’s Second Law relating net force, mass, and acceleration

• Newton’s Third Law stating forces occur in equal and opposite pairs

• Newton’s First Law (law of inertia) about resisting changes in motion

• Conservation of momentum independent of external net forces

Which of the following is a field force (non-contact)?

• Friction between two sliding surfaces in direct contact with one another

• Tension transmitted through a taut rope due to pulling at its ends

• Gravitational force acting at a distance between masses

• Normal reaction of a surface supporting an object from below

A student pushes a heavy cabinet, but it does not budge. Which statement is most accurate?

• The applied push is smaller than the opposing forces (mainly static friction and resistance), so the net force is zero

• Newton’s Second Law is violated because an applied force should always cause motion in real situations

• Friction is completely absent in this situation, so only gravity prevents motion of the cabinet

• The cabinet has no inertia at rest; inertia only appears when the object is already moving

According to Newton’s Second Law, if the net force on an object is doubled while its mass is constant, the object’s acceleration—

• Doubles in magnitude in the direction of the net force

• Is reduced to half because the inertia dominates the motion strongly

• Remains unchanged since velocity, not acceleration, depends on force

• Reverses direction due to the larger unbalanced force acting on the body

In a head-on collision between a truck and a car, which exerts the greater force on the other during the impact interval?

• The truck exerts a larger force because it has greater mass and momentum compared with the car

• The car exerts a larger force because it undergoes a greater change in velocity during the collision event

• Each exerts the same magnitude of force on the other, though their accelerations differ due to different masses

• Forces are negligible at the moment of impact because they cancel out through conservation principles

A rocket lifts off primarily because—

• Gravity becomes weaker with altitude and eventually stops acting during ascent

• Hot exhaust gases are expelled downward, and an equal opposite force (thrust) pushes the rocket upward

• Inertia keeps the rocket moving upward after an initial push regardless of other forces

• Decreasing mass alone causes the rocket to rise without any significant reaction force

A magician yanks a tablecloth quickly and the dishes hardly move. The trick relies on—

• Balanced forces that ensure the net force on the dishes is exactly zero at all times

• Large forward acceleration on the dishes causing them to keep up with the cloth’s sudden motion

• The dishes’ inertia; with low friction and a rapid pull, their state of rest changes very little

• Weak gravitational pull that has minimal effect on tabletop objects during short time intervals

Which statement correctly compares mass and weight?

• Both mass and weight change with location because gravity varies across different celestial bodies

• Mass can change between Earth and Moon, but weight remains constant since the object is the same

• Mass is constant, while weight depends on the local gravitational field strength (g) acting on the mass

• Both are forces with identical units and definitions in everyday and scientific usage