Final answer:
Questions involve understanding Newton's laws concerning objects moving with constant velocity, requiring a zero net force. Force calculation and free-body diagram skills are tested.
Step-by-step explanation:
The question pertains to the application of Newton's laws of motion, specifically scenarios where an object is moving with a constant velocity under the influence of multiple forces, and the application of these principles in free-body diagrams and calculations of force and acceleration. To move an object with constant velocity, such as a cart pushed by a nurse, the net force must be zero, which means that the force exerted by the nurse must be equal and opposite to the sum of all other forces, including friction. In a free-body diagram, one would display all the acting forces, and by applying Newton's second law, F=ma, where a is the acceleration and m is the mass, the necessary force to exert can be determined when taking into account the angle of the applied force and the force of friction.