What is systematic replication? developing a plan for how data will be collected in order to answer a research question

repeating a study as closely as possible to its original design in order to show reliability
developing a research question or hypothesis in order to make a prediction

repeating a study with differences in design in order to show external validity

Assume this car is driven off a cliff . how many arrows of force need to be drawn in the free body diagram? assume no air resistance -five -one -three -four

Two steel balls, each of mass m, are welded to a light rod of length l and negligible mass and are initially at rest on a smooth horizontal surface. a horizontal force of magnitude f is suddenly applied to the rod as shown. determine (a) the instantaneous acceleration a of the mass center g and (b) the corresponding rate at which the angular velocity of the assembly about g is changing with time.

The electric field direction is defined by the direction of the force felt by (select one of the following answers): 1. a negative charge. 2. a positive charge. 3. both positive and negative charges.