(1) There are _____ main types of motion.
(2) An accelerated body is one whose velocity is _____ .
(3) The unit 〖cm s〗^(-1)is the unit of _____ .
(4) If a body starts from rest , its initial velocity is _____ .
(5) The unit of speed and velocity are the _____ .
(6) If the starting point and the end point are the same , the displacement is _____ .
(7) A body with decreasing positive velocity has a _____ acceleration.
(8) _____ is the magnitude of the velocity.
) By Newton’s second law , the acceleration is directly proportional to ……… .
(3) Newton’s third law express the idea of ………. .
(4) Action force and reaction force cannot ……… out each other.
(5) Force has both magnitude and ……. .
(6) Force is a ……… quantity.
(7) The SI unit for force is ……….. .
(8) Mass is a measure of ………. .
(9) The attracting force of the earth acting on