1. What is force and inertia?
Answer: Force is a push or pull on an object that causes it to change its velocity or direction. Inertia is the property of an object to resist changes in its state of motion; an object at rest stays at rest, and an object in motion stays in motion unless acted upon by an external force.
2. State Newton’s First Law of Motion.
Answer: Newton’s First Law of Motion, also known as the law of inertia, states that an object will remain at rest or in uniform motion in a straight line unless acted upon by an external force.
3. Define momentum.
Answer: Momentum is the product of an object’s mass and its velocity. It is a vector quantity, having both magnitude and direction.
4. State Newton’s Second Law of Motion.
Answer: Newton’s Second Law of Motion states that the rate of change of momentum of an object is directly proportional to the net force acting on it and occurs in the direction of the force. Mathematically, F = ma, where F is the force, m is the mass, and a is the acceleration.
5. What is an impulse?
Answer: Impulse is the product of the force applied to an object and the time duration over which the force is applied. It equals the change in momentum of the object.
6. State Newton’s Third Law of Motion.
Answer: Newton’s Third Law of Motion states that for every action, there is an equal and opposite reaction.
7. Explain the law of conservation of linear momentum.
Answer: The law of conservation of linear momentum states that if no external force acts on a system of particles, the total linear momentum of the system remains constant.
8. Provide an application of the law of conservation of linear momentum.
Answer: One application of the law of conservation of linear momentum is in collisions. In an isolated system, the total momentum before and after a collision is conserved.
9. What is the equilibrium of concurrent forces?
Answer: Equilibrium of concurrent forces occurs when multiple forces acting at a single point cancel each other out, resulting in no net force and thus no change in motion.
10. Differentiate between static and kinetic friction.
Answer: Static friction is the frictional force that prevents relative motion between two surfaces in contact and acts when the surfaces are at rest relative to each other. Kinetic friction is the frictional force that opposes the relative motion between two surfaces in contact and acts when the surfaces are moving relative to each other.
11. State the laws of friction.
Answer: The laws of friction are: (1) The frictional force is directly proportional to the normal force. (2) The frictional force is independent of the apparent area of contact. (3) The frictional force depends on the nature of the surfaces in contact.
12. What is rolling friction?
Answer: Rolling friction is the force that resists the motion of a rolling object on a surface. It is generally much smaller than static or kinetic friction.
13. Describe the dynamics of uniform circular motion.
Answer: Uniform circular motion refers to the motion of an object moving at a constant speed along a circular path. The direction of the object’s velocity changes continuously, requiring a centripetal force directed towards the center of the circle.
14. What is centripetal force?
Answer: Centripetal force is the inward force required to keep an object moving in a circular path. It acts perpendicular to the object’s velocity and towards the center of the circle.
15. Provide an application of centripetal force.
Answer: An application of centripetal force is a vehicle making a turn on a circular road. The friction between the tires and the road provides the centripetal force necessary to keep the vehicle moving along the curved path.
16. How does a vehicle navigate a level circular road?
Answer: On a level circular road, the frictional force between the tires and the road surface provides the necessary centripetal force to keep the vehicle moving in a circular path.
17. How does a vehicle navigate a banked road?
Answer: On a banked road, the normal force exerted by the road on the vehicle has a horizontal component that provides the necessary centripetal force, reducing the reliance on friction.
18. Explain the concept of impulse-momentum theorem.
Answer: The impulse-momentum theorem states that the impulse on an object is equal to the change in its momentum. Mathematically,
19. What is the significance of Newton’s Third Law in real-life situations?
Answer: Newton’s Third Law explains many real-life situations such as walking, where the foot pushes backward on the ground and the ground pushes forward on the foot, propelling the person forward.
20. Describe the relationship between centripetal force and the speed of an object in circular motion.
Answer: The centripetal force required to keep an object moving in a circular path is directly proportional to the square of the object’s speed. Mathematically,
where Fc is the centripetal force, m is the mass, v is the speed, and r is the radius of the circular path.