Momentum is a physical quantity that describes the motion of an object, defined as the product of its mass and velocity (p=mv). It is a vector quantity, meaning it has both magnitude and direction, and its SI unit is kilogram meter per second (kgยทm/s). Momentum is closely related to Newton's second law of motion, which states that the force applied to an object is equal to the rate of change of its momentum. The law of conservation of momentum states that in an isolated system, the total momentum before and after a collision remains constant, provided no external forces act on the system. This principle is essential in understanding interactions such as collisions between objects.
What is momentum?
Momentum is a physical quantity that represents the motion of an object, defined as the product of its mass (๐) and velocity (๐ฃ), expressed as ๐=๐๐ฃ.
Is momentum a scalar or a vector quantity? Why?
Momentum is a vector quantity because it has both magnitude and direction, and its direction is the same as the object's velocity.
What does the law of conservation of momentum state?
The law of conservation of momentum states that in an isolated system, the total momentum before a collision is equal to the total momentum after the collision, provided no external forces act on the system.
How is momentum related to mass and velocity?
Momentum is directly proportional to both mass and velocity. If either mass or velocity increases, the momentum of the object increases accordingly.
Give an example of momentum conservation in real life.
In a game of billiards, when one ball strikes another, the momentum lost by the first ball is transferred to the second ball, demonstrating the conservation of momentum.
Momentum is a vector quantity because:
a) It depends on velocity only
b) It depends on mass only
c) It has magnitude and direction
d) It changes with speed
Answer: c) It has magnitude and direction
Impulse is defined as:
a) Change in velocity
b) Product of force and time
c) Rate of change of acceleration
d) Mass times velocity
Answer: b) Product of force and time
What does the law of conservation of momentum state?
a) Momentum can be created or destroyed
b) Total momentum of an isolated system remains constant
c) Momentum is inversely proportional to velocity
d) Momentum is always zero in a closed system
Answer: b) Total momentum of an isolated system remains constant
If the mass of an object is doubled and the velocity is halved, the momentum will:
a) Double
b) Remain the same
c) Be halved
d) Be quadrupled
Answer: b) Remain the same
A ball of mass 2 kg moves with a velocity of 3 m/s. What is its momentum?
a) 5 kgm/s
b) 6 kgm/s
c) 9 kgm/s
d) 12 kgm/s
Answer: b) 6 kgm/s