LAWS OF MOTION 6.

How does friction affect an object’s state of motion according to

Newton’s first law?

1) What does Newton's first law of motion state about the motion of an • Friction is an external force that opposes motion. It can cause a
object? moving object to slow down or stop, demonstrating that an
external force is needed to change an object's state of motion.
• Newton's first law states that an object at rest will remain at
rest, and an object in motion will continue in motion with the 7. Describe a scenario in which an object continues in motion without
same speed and in the same direction unless acted upon by an any external force acting on it.
external force.
• In the vacuum of space, a spacecraft can drift indefinitely in a
2) Define inertia in your own words. straight line without any external forces acting on it, as there is
no air resistance or friction to slow it down.
• Inertia is the property of an object to resist changes in its state
of motion. It means that an object will stay still or keep moving
unless something forces it to change.
8. Why do passengers in a car lurch forward when the car suddenly
3. How does mass relate to inertia? stops?

• The greater the mass of an object, the greater its inertia. This • Passengers lurch forward due to inertia; their bodies want to
means heavier objects require more force to change their continue moving at the same speed the car was traveling. When
motion compared to lighter objects. the car stops, only the car is acted upon by the brakes, while the
passengers continue in motion.
4. Give an example of an everyday situation that demonstrates
Newton's first law. 9. How does Newton's first law apply to objects in space, where
gravitational forces are weaker?
• A classic example is a ball rolling on a smooth surface; it will
continue rolling in a straight line until friction or another force • In space, objects continue in motion with constant velocity
(like a wall) stops it. unless acted upon by a force. Since there is minimal
gravitational pull or resistance, objects can move freely without
5. What is the difference between a balanced force and an unbalanced interruption.
force in the context of Newton's first law?
10. Can an object at rest exhibit inertia? Explain your answer.
• Balanced forces result in no change in an object's motion (it
stays at rest or moves at a constant speed), while unbalanced • Yes, an object at rest exhibits inertia because it resists any
forces cause a change in motion, either accelerating or change to its state. It will remain at rest unless a force acts upon
decelerating the object. it, demonstrating its inertial property.
Question: What is the significance of the term "external force" in Answer: Both the bowling ball and the marble would continue rolling
Newton's first law? indefinitely at constant speeds and in the same direction, as there
would be no external forces acting upon them to stop or change their
Answer: An external force is any force that comes from outside the
motion.
object in question. It is significant because it is the factor that can
change an object's state of motion—either bringing a stationary object
into motion or altering the motion of a moving object.
Question: Describe how inertia affects the motion of objects in a
rotating frame of reference, like a spinning carousel.
Question: How does Newton's first law relate to the concept of Answer: In a rotating frame, inertia causes objects to want to move in a
equilibrium? straight line (tangentially). This is why riders on a carousel feel pushed
outward; they tend to continue moving straight while the carousel turns
Answer: An object is in equilibrium when the net force acting on it is
underneath them.
zero. This means all forces are balanced, and according to Newton's
first law, the object will either remain at rest or continue moving at a
constant velocity.
Question: Why do objects in microgravity environments, such as the
International Space Station, float?
Question: Can you explain why a seatbelt is important in a vehicle in Answer: Objects float in microgravity because they are in free fall
terms of inertia? alongside the station. In this state, there are no significant forces acting
on them to change their motion, so they continue moving in the same
Answer: A seatbelt restrains passengers and prevents them from
direction at constant velocity.
continuing forward due to inertia during sudden stops or collisions. It
provides the necessary force to change their state of motion, helping to
protect them from injury.
Question: How does air resistance act as an external force on falling
objects?
Question: What role does inertia play in the design of safety features in Answer: Air resistance opposes the motion of falling objects, acting as
cars? an external force that can slow them down. It reduces the acceleration
due to gravity until a balance is reached, leading to terminal velocity.
Answer: Inertia is considered in safety features such as airbags and
crumple zones. These features are designed to absorb and reduce the
forces acting on passengers during a collision, helping to counteract
the effects of inertia.
Question: What would happen to a bowling ball and a marble if they
were both rolling on a frictionless surface?
Question: Explain how Newton's first law applies to the motion of Question: How does increasing an object’s mass affect its acceleration
planets in the solar system. when a constant force is applied?
Answer: Planets move in orbits due to the gravitational force exerted by Answer: If a constant force is applied to an object and its mass
the sun. If this force were to suddenly vanish, planets would continue increases, its acceleration will decrease. This is because acceleration
moving in a straight line at constant speed, demonstrating their inertia is inversely proportional to mass ().
according to Newton's first law.

Question: Give an example of a situation where Newton's second law is

Question: What does Newton's second law of motion state? applied in real life.
Answer: Newton's second law states that the acceleration of an object Answer: A common example is pushing a shopping cart. The harder
is directly proportional to the net force acting on it and inversely you push (increasing the force), the faster the cart accelerates. If the
proportional to its mass. This can be expressed with the formula , cart is loaded with heavy items (increasing mass), it will accelerate
where is the net force, is mass, and is acceleration. more slowly with the same amount of force.

Question: How is momentum defined in physics? Question: What is the principle of conservation of momentum?
Answer: Momentum is defined as the product of an object's mass and Answer: The principle of conservation of momentum states that in a
its velocity. It is a vector quantity, represented by the formula , where is closed system, the total momentum before an event (like a collision) is
momentum, is mass, and is velocity. equal to the total momentum after the event, provided no external
forces act on the system.

Question: What is the relationship between force and momentum

according to Newton's second law? Question: How does a rocket launch demonstrate Newton's second
law and momentum?
Answer: The rate of change of momentum of an object is equal to the
net force acting on it. Mathematically, this is expressed as , where is Answer: During a rocket launch, the engines expel gas downward
the change in momentum and is the change in time. (creating a force), which results in an upward acceleration of the rocket
due to Newton's second law. The momentum of the rocket increases as
it moves upward, and the momentum of the expelled gas is equal and
opposite.
Question: How can you increase an object's momentum without Question: Can you give an example of Newton's third law in action?
changing its mass?
Answer: A classic example is when you jump off a small boat. As you
Answer: You can increase an object's momentum by increasing its push down and back against the boat (action), the boat pushes you up
velocity. Since momentum is the product of mass and velocity (), if and forward (reaction), causing it to move in the opposite direction.
mass remains constant, a higher velocity results in greater momentum.

Question: How does Newton's third law explain the flight of a bird?
Question: What happens to momentum during an elastic collision?
Answer: When a bird flaps its wings down (action), it exerts a
Answer: In an elastic collision, both momentum and kinetic energy are downward force on the air. The air exerts an equal and opposite force
conserved. This means the total momentum of the colliding objects upward (reaction), allowing the bird to lift off the ground.
before the collision equals the total momentum after the collision.

Question: How does a rocket launch illustrate Newton's third law?

Question: How do seatbelts relate to Newton's second law and
Answer: During a rocket launch, the engines expel gas downwards
momentum in car accidents?
(action), and in response, the rocket is pushed upwards (reaction) due
Answer: In a car accident, the sudden stop of the vehicle applies a to the equal and opposite force of the expelled gas.
force that changes the momentum of the passengers. Seatbelts
provide the necessary force to decelerate the passengers safely,
preventing them from continuing forward due to their inertia. Question: What role does friction play in Newton's third law?
Answer: Friction is a force that acts in the opposite direction of motion.
When a person pushes against a wall (action), the wall exerts an equal
Question: What does Newton's third law of motion state?
and opposite force back against the person (reaction), which is felt as
Answer: Newton's third law states that for every action, there is an resistance.
equal and opposite reaction. This means that forces always occur in
pairs; when one object exerts a force on another, the second object
exerts a force of equal magnitude and opposite direction back on the Question: In a collision between two cars, how does Newton's third law
first object. apply?
Answer: When two cars collide, each car exerts a force on the other
(action), and simultaneously, each car experiences an equal and
opposite force from the other (reaction). This results in damage and
changes in motion for both vehicles.
Question: How does a swimmer move through water according to
Newton's third law?
Answer: A swimmer pushes the water backward (action), and as a
reaction, the water pushes the swimmer forward, allowing them to
move through the water.
Question: What happens to a balloon when air is released from it?
Answer: When air rushes out of a deflated balloon (action), the balloon
itself is propelled in the opposite direction (reaction), demonstrating
Newton's third law.

Question: How does walking illustrate Newton's third law?

Answer: When you walk, you push the ground backward with your foot
(action), and the ground pushes you forward with an equal and
opposite force (reaction), allowing you to move.

Question: Why do astronauts experience a sensation of floating in

space, despite Newton's third law still applying?
Answer: Astronauts float because they are in free fall with the
spacecraft. While they still exert forces on each other and the
spacecraft (action), there is no opposing force (reaction) acting on
them from the ground, as there is no ground in space to push against.