<span>By Newton's second law of motion, we know that the resultant force acting on a body is directly proportional to the mass of the body and directly proportional to its acceleration. In system international (SI) units, the value of the constant of proportionality constant is 1. Therefore, the equation for Newton's second law of motion becomes: F = ma, where F is the resultant force, m is the mass and a is the acceleration of the object. Substituting the values of m and a into this formula, we get the result: F = 12 x 4 = 48. The SI unit for force is the Newton; therefore, <u>the answer is 48 Newtons.</u></span>
Psychological development, the development of human beings' cognitive, emotional, intellectual, and social capabilities and functioning over the course of the life span, from infancy through old age. It is the subject matter of the discipline known as developmental psychology.
Answer:112.82 m/s
Explanation:
Given
range of arrow=68 m
as the arrow travels it acquire a vertical velocity 
-------1
Range is given by
R=ut
where u=initial velocity
substitute the value of t in eqn 1
--------2
and 
substitute it in 2
u=112.82 m/s
