When a spacecraft travels away from earth, the gravitational force acting on it

increases

decreases

increases first and then decreases

decreases first and then increases

Which of the following is considered to be a vector?               a.  temperature    b.  velocity    c.  time    d.  mass

What are similarities and differences between refraction, reflection, diffraction and absorption?

Asubject in a clinical research trial experiences a serious, unanticipated adverse drug experience. how should the investigator proceed, with respect to the irb, after the discovery of the adverse event occurrence? a. do not report the adverse drug experience to the irb since it is a common adverse experience.b. report the adverse drug experience to the irb only if there are several other occurrences.c. report the adverse drug experience as part of the continuing review report.d. report the adverse drug experience in a timely manner, in keeping with the irb's policies and procedures, using the forms or the mechanism provided by the irb.