Q: The formula F = ma belongs to which law of motion?
Answer: Second Law
Explanation: Newton's Second Law provides the quantitative relationship between force, mass, and acceleration. It states that the acceleration of a body is directly proportional to the net force acting on it. This is arguably the most famous equation in classical physics.
Q: For every action, there is an equal and opposite reaction. This is?
Answer: Newton's Third Law
Explanation: This statement is the common definition of Newton's Third Law of Motion. It explains that forces always exist in pairs during interactions between objects. These forces are equal in magnitude but opposite in direction.
Q: A body of mass 10 kg has a weight on Earth of approximately?
Answer: 98 N
Explanation: Weight is calculated as mass (10 kg) multiplied by gravity (9.8 m/s²), which equals 98 Newtons. Weight is a force and should always be expressed in Newtons in scientific contexts. It represents the gravitational pull of the Earth on the mass.
Q: Which law is also known as the Law of Inertia?
Answer: First Law
Explanation: Newton's First Law is called the Law of Inertia because it describes the inherent tendency of objects to resist motion changes. Galileo first developed this concept, which Newton later formalized. It applies to both objects at rest and those in uniform motion.
Q: Force is a measure of the rate of change of?
Answer: Momentum
Explanation: The Second Law of Motion defines force as the time rate of change of linear momentum. In most cases where mass is constant, this simplifies to mass times acceleration. This definition is essential for understanding complex systems like rockets.
Q: A gun recoils because of the?
Answer: Third Law
Explanation: The backward motion of a gun after firing is a direct consequence of the Third Law. The forward force on the bullet results in an equal backward force on the gun. This pair of forces ensures that the total momentum of the system remains zero.
Q: The inertia of an object depends primarily on its?
Answer: Mass
Explanation: Mass is the only factor that determines the amount of inertia an object possesses. Heavier objects are harder to start or stop because they have more mass and thus more inertia. This is a fundamental principle of classical mechanics.
Q: A goalkeeper pulls his hands back while catching a ball to?
Answer: Reduce force
Explanation: By pulling the hands back, the goalkeeper increases the time over which the ball's momentum changes to zero. According to Newton's Second Law, this increased time results in a smaller impact force. This practical application prevents pain and injury to the hands.
Q: Walking on a slippery road is difficult because of?
Answer: Low Friction
Explanation: Low friction on a slippery surface makes it difficult to apply a backward force on the ground. Without this action, the ground cannot provide the forward reaction force needed for walking. This is a classic example of Newton's Third Law requiring a contact force.
Q: Newton's Third Law states that?
Answer: Every action has an equal and opposite reaction
Explanation: Newton's Third Law states that for every action, there is an equal and opposite reaction. The two forces act on different bodies simultaneously. For example, when you push a wall, the wall pushes back with equal force.