5.3 dynamics ☠

Question 1

define Newton’s 1st law of motion

Answer 1

an object continues in its state of rest or constant velocity in the absence of an external resultant force

Question 2

define Newton’s 2nd law of motion

Answer 2

the rate of change of momentum of an object is directly proportional to the external resultant force acting on it. momentum changes in the same direction as the force

Question 3

define Newton’s 3rd law of motion

Answer 3

when object A exerts a force on object B, object B exerts a force of the same type that is equal in magnitude and opposite in direction on object A

Question 4

state the principle of conservation of momentum

Answer 4

the principle of conservation of momentum states that the total momentum in a system of interacting bodies is constant, provided that no external resultant force acts on the system.

Question 5

distinguish between mass and weight

Answer 5

mass is the property of a body which resists change in motion while weight is the force acting on a mass due to a gravitational field

Question 6

distinguish between momentum and impulse

Answer 6

momentum is the product of the mass of a movig object and its velocity. impulse is the integral of the force over the time interval during which the force acts