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- Motion refers to a change in position and can be explained by the distance traveled or the displacement.
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Speed is defined as the distance covered per unit of time, while velocity refers to displacement per unit of time.
When an object moves in a circular path at a constant speed, it is said to be in uniform circular motion.
Graphs can be used to represent both uniform and non-uniform motions of objects.
Acceleration is the rate of change of velocity over time.
An object’s motion can be either uniform or non-uniform, based on whether its velocity remains constant or varies.
The motion of an object with uniform acceleration is described by the following equations:
1. v = u + at
2. s = ut + ½ at2
3. 2as = v2 u2
where u is the initial velocity, v is the final velocity, a is the uniform acceleration, t is the time, and s is the distance covered in that time.
1. What is the natural state of an object according to classical observation?
(A) Motion
(B) Rest
(C) Rotation
(D) Oscillation
Explanation: Classical observation suggests that rest is the natural state of an object until acted upon by an external force.
2. Which scientist challenged the classical notion that rest is the natural state of an object?
(A) Albert Einstein
(B) Isaac Newton
(C) Galileo Galilei
(D) Niels Bohr
Explanation: Galileo Galilei proposed that an object in motion would remain in motion unless acted upon by an external force, challenging the classical notion that rest is the natural state.
3. What is the basic unit of force in the International System of Units (SI)?
(A) Kilogram
(B) Newton
(C) Pascal
(D) Joule
Explanation: The unit of force in the SI system is Newton (N), defined as the force required to accelerate a 1 kg mass by 1 m/s².
4. What does Newton's First Law of Motion state?
(A) Force equals mass times acceleration.
(B) For every action, there is an equal and opposite reaction.
(C) An object at rest stays at rest, and an object in motion stays in motion unless acted upon by an external force.
(D) The force on an object is proportional to the rate of change of its momentum.
Explanation: Newton's First Law, also known as the law of inertia, describes the tendency of objects to resist changes in their motion.
5. The tendency of an object to resist changes in its state of motion is called:
(A) Force
(B) Momentum
(C) Inertia
(D) Acceleration
Explanation: Inertia is the property of an object that resists changes to its motion, whether the object is at rest or moving.
6. Which of the following is a measure of an object's inertia?
(A) Velocity
(B) Acceleration
(C) Force
(D) Mass
Explanation: Mass is a measure of an object's inertia; heavier objects have more inertia.
7. According to Newton's Second Law of Motion, the acceleration of an object is directly proportional to:
(A) Mass
(B) Force
(C) Momentum
(D) Inertia
Explanation: Newton's Second Law states that the acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass (F = ma).
8. What happens to an object when balanced forces act on it?
(A) It accelerates.
(B) It remains stationary or moves with constant velocity.
(C) It changes direction.
(D) It deforms.
Explanation: Balanced forces do not change the motion of an object; they maintain its state of rest or uniform motion.
9. Which of the following is an example of an unbalanced force?
(A) A book lying on a table
(B) A car moving at a constant speed
(C) A ball rolling down a hill
(D) A satellite orbiting Earth
Explanation: An unbalanced force causes a change in motion, such as a ball accelerating as it rolls downhill.
10. What is the unit of momentum in the SI system?
(A) kg m/s
(B) N m
(C) Joule
(D) Pascal
Explanation: Momentum is the product of mass and velocity and is measured in kilograms meters per second (kg m/s).
11. If a body is at rest, what can we say about the forces acting on it?
(A) Forces are unbalanced.
(B) There is no force acting on it.
(C) Forces are balanced.
(D) It is in vacuum.
Explanation: If a body is at rest, the forces acting on it are balanced, resulting in no net force.
12. The law of inertia is another name for:
(A) Newton's First Law
(B) Newton's Second Law
(C) Newton's Third Law
(D) Law of Universal Gravitation
Explanation: The law of inertia is Newton's First Law, which states that objects resist changes in their motion.
13. Which law explains the recoil of a gun when a bullet is fired?
(A) First Law of Motion
(B) Second Law of Motion
(C) Third Law of Motion
(D) Law of Gravitation
Explanation: Newton's Third Law states that for every action, there is an equal and opposite reaction, which explains the recoil of a gun when a bullet is fired.
14. What is the mathematical formula for Newton's Second Law of Motion?
(A) F = ma
(B) F = mv
(C) F = 1/2mv²
(D) F = G(m1*m2)/r²
Explanation: Newton's Second Law is mathematically expressed as F = ma, where F is force, m is mass, and a is acceleration.
15. When a car suddenly stops, passengers tend to lurch forward. This is due to:
(A) Newton's First Law
(B) Newton's Second Law
(C) Newton's Third Law
(D) Law of Conservation of Momentum
Explanation: Due to inertia (Newton's First Law), passengers tend to continue in their state of motion when the car stops suddenly.
16. The force that opposes the relative motion between two surfaces in contact is called:
(A) Gravitational force
(B) Tension
(C) Friction
(D) Centripetal force
Explanation: Friction is the force that opposes motion between two surfaces in contact.
17. Which of the following is not an effect of force?
(A) Change in shape
(B) Change in speed
(C) Change in direction
(D) Change in mass
Explanation: Force can change an object's speed, direction, and shape, but it cannot change its mass.
18. When a rubber ball is pressed, it changes its shape. This is an example of:
(A) Balanced force
(B) Unbalanced force
(C) Gravitational force
(D) Elastic force
Explanation: The ball changes its shape because the forces applied on it are balanced, causing deformation without causing motion.
19. Which of the following best describes the motion of an object when an unbalanced force acts on it?
(A) The object remains at rest.
(B) The object moves with constant velocity.
(C) The object accelerates.
(D) The object deforms.
Explanation: An unbalanced force causes a change in the object's velocity, resulting in acceleration.
20. What happens to the momentum of a car if its velocity is doubled?
(A) Momentum is halved.
(B) Momentum remains the same.
(C) Momentum is doubled.
(D) Momentum is quadrupled.
Explanation: Momentum is the product of mass and velocity, so if velocity is doubled, momentum also doubles.
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