Isaac Newton Flashcards
Q: What was the first definition Newton provided in his book?
A: The first definition states that the quantity of matter is a measure arising from its density and bulk, which defines mass as being the product of density and volume.
Q: How did Newton define the quantity of motion?
A: Newton defined the quantity of motion (momentum) as a measure arising from both the velocity and the quantity of matter, meaning momentum is equal to mass times velocity.
Q: What is inertia, according to Newton’s laws of motion?
A: Inertia is the property of an object to remain in its current state of motion or rest unless acted upon by an external force. It is the tendency to resist changes in motion.
Q: How does Newton define force?
A: Force is defined as an action exerted upon a body to change its state of motion or rest, essentially causing acceleration.
Q: What is Newton’s First Law of Motion?
A: Newton’s First Law, also known as the law of inertia, states that an object in a state of rest or uniform motion will remain in that state unless acted upon by an external force.
Q: What is the relationship between force, mass, and acceleration as described in Newton’s Second Law of Motion?
A: Newton’s Second Law states that the force applied to an object is equal to the mass of the object times its acceleration (F = ma). This means a larger force is needed to accelerate a heavier object.
Q: What is Newton’s Third Law of Motion?
A: Newton’s Third Law states that for every action, there is an equal and opposite reaction. This means if one object exerts a force on another, the second object exerts an equal and opposite force on the first.
Q: How is weight different from mass?
A: Mass is a measure of the quantity of matter in an object, while weight is the force exerted on that object due to gravity. Weight is mass times gravitational acceleration (W = mg).
Q: What is the unit of force, and how is it defined?
A: The unit of force is the Newton (N), defined as one kilogram meter per second squared (kg·m/s²). It is the force required to accelerate a one-kilogram object by one meter per second squared.
Q: What happens when the forces on an object are balanced?
A: When forces on an object are balanced, the sum of all forces equals zero, and the object remains in equilibrium, meaning it will not accelerate or change its motion.
Q: What is the friction force, and how does it act on objects?
A: The friction force is a resistive force that opposes the motion between two surfaces in contact. It acts in the opposite direction of the applied force and can balance other forces, preventing acceleration
Q: What is the role of the normal force in Newtonian mechanics?
A: The normal force is a repulsive force exerted perpendicular to a surface, preventing objects from passing through each other. It balances the gravitational force acting on an object resting on a surface.
Q: What is Newton’s Third Law of Motion?
A: Newton’s Third Law states that for every action, there is an equal and opposite reaction. When one object exerts a force on another, the second object exerts an equal force back in the opposite direction.
Q: How does Newton’s Third Law apply to rocket propulsion?
A: In rocket propulsion, the rocket expels fuel downward (action), and the fuel pushes the rocket upward with an equal and opposite force (reaction). This allows the rocket to accelerate upwards.
Q: In the astronaut and spaceship example, why do the astronaut and the spaceship experience different accelerations?
A: Although the forces on the astronaut and spaceship are equal (according to Newton’s Third Law), their accelerations differ because the astronaut has a much smaller mass than the spaceship. According to Newton’s Second Law (a= F/m), a smaller mass results in greater acceleration.
