Newton’s Laws of Motion and MCQ on Newton’s laws of motion
Newton’s First Law of Motion
The initial principle of motion coined by Sir Isaac Newton is
commonly referred to as the principle of inertia, which can also be termed as
the first law of motion. The law of inertia asserts that an object that is
stationary will persist in its state of rest, while an object in motion will
sustain its motion at a steady pace, until it is influenced by an external
stimulus. This implies that an object is unable to alter its movement on its
own and necessitates an external impetus to transform its motion.
Newton's second law of
motion
The second principle of motion established by Sir Isaac
Newton is known as the second law of motion, which highlights that the force
exerted on an object is proportional to its mass and acceleration. In simpler
words, when a larger force is applied to an object, it will have a greater
acceleration, while an object with a larger mass requires more force to
accelerate it.
Newton's third law of motion
The third
principle of motion introduced by Sir Isaac Newton is commonly referred to as
the third law of motion, which can be described as the notion that "every
action has an equal and opposite reaction." This infers that whenever two
objects interact, the forces they apply on each other are equal in size, yet
opposite in direction. As an illustration, if an individual pushes against a
wall, the wall will respond by pushing back against the individual with a force
that is equal in magnitude but opposite in direction.
Real-world examples of Newton's first law of motion:
- A passenger in a car not wearing a seatbelt will continue to move forward at a constant speed in the event of a sudden stop until an external force, such as the dashboard or airbag, stops them
- A soccer ball will remain at
rest until an external force, such as a player kicking it, acts upon it.
- An astronaut in space will
continue to float in a straight line at a constant speed unless they are
acted upon by an external force, such as using a jetpack to change their
direction.
- A book sitting on a table will
remain in place until an external force, such as a gust of wind or someone
picking it up, acts upon it.
- A boat drifting on a lake will
continue to drift in a straight line at a constant speed until an external
force, such as wind or water currents, alters its course.
Real-world examples of Newton's second law of motion:
- A car will accelerate faster
when the driver presses harder on the gas pedal, because more force is
being applied to the car.
- A heavier object requires more
force to move it at the same rate as a lighter object. For example, pushing
a shopping cart full of groceries requires more force than pushing an
empty cart.
- A ball thrown with more force
will travel farther and faster than a ball thrown with less force.
- An athlete running faster exerts
more force on the ground with each step, which propels them forward with
greater acceleration.
- A rocket carrying a heavier
payload requires more force to launch it into orbit at the same speed as a
lighter payload.
Real-world examples of Newton's third law of motion:
- When an individual leaps off a
diving board, they apply a downward force to the board using their feet,
and the board exerts an upward force that is equal in magnitude but
opposite in direction, propelling the person upwards.
- When a bird flaps its wings
downwards, it generates lift by pushing the air downward. Concurrently,
the air exerts an equal and opposite force by pushing back up on the bird's
wings, which permits the bird to fly.
3.
When
a ball bounces on the ground, it applies a force on the ground, and the ground
responds by exerting an equal and opposite force on the ball, causing it to
rebound upward.
4.
When
an individual sits in a chair, their weight exerts a force on the chair, and
the chair counteracts with an equal and opposite force that supports their
weight.
5.
When
an individual paddles a canoe, they push water backward with their paddle, and
the water reciprocates by pushing back on the paddle with an equal and opposite
force, propelling the canoe forward.
According to Newton's
first law of motion, an object at rest will:
a) Stay at
rest
b) Start
moving
c)
Accelerate
d)
Decelerate
Answer: a)
Stay at rest
According to Newton's
second law of motion, the acceleration of an object is directly proportional
to:
a) The
object's mass
b) The
object's velocity
c) The
object's position
d) The
object's density
Answer: a)
The object's mass
According to Newton's
third law of motion, every action has an equal and opposite reaction. Which of
the following is an example of this law in action?
a) A car
accelerating down the road
b) A book
sitting on a table
c) A bird
flying through the air
d) A rocket
launching into space
Answer: d) A
rocket launching into space
Which of the following
is an example of Newton's first law of motion?
a) A ball
thrown with more force will travel farther and faster than a ball thrown with
less force.
b) A person
standing still on a moving train is thrown forward when the train suddenly
stops.
c) A heavy
object requires more force to move it at the same rate as a lighter object.
d) An
athlete running faster exerts more force on the ground with each step, which
propels them forward with greater acceleration.
Answer: b) A
person standing still on a moving train is thrown forward when the train
suddenly stops.
According to Newton's
second law of motion, which of the following would require the most force to
accelerate at the same rate as the others?
a) A tennis
ball
b) A
baseball
c) A bowling
ball
d) All of
the above require the same amount of force to accelerate at the same rate.
Answer: c) A
bowling ball