Final answer:
The force being applied to a cart with a fan involves a variety of physical concepts such as Newton's second law, work, and the components of force. Work done by forces such as gravity and normal forces is zero on a horizontal surface, whereas the horizontal component of an applied force can do work, as seen in scenarios involving a baggage tractor or a nurse pushing a cart.
Step-by-step explanation:
Forces on a Cart and Work Done
When discussing the force applied to a cart with a fan, or any force applied to an object, we are examining a physics concept called Newton's second law, which states that the acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass. In the case of a cart and fan, the forces may include the force of the fan, frictional forces, normal forces, and the weight of the cart due to gravity.
In terms of the work done by each force on the cart over a distance D, work is defined as the dot product of force and displacement. The work done by gravity is typically zero when moving something horizontally because the displacement is perpendicular to the force of gravity.
On flat horizontal surfaces, since there is no vertical displacement, the work done by the gravitational force (Fw) is zero. The normal forces (FN1) and (FN2) also do no work for the same reason.
However, if the force applied has a component in the direction of the displacement, that force does work. For example, if a nurse applies a force at a downward angle to push a cart, only the horizontal component of the applied force will work. Similarly, if a shopper pushes a grocery cart against frictional force, the work done by the shopper must overcome the work done by friction.
The force exerted by a professor on a cart may be different than the force exerted by the professor backward on the floor due to the professor’s acceleration in the opposite direction. In a situation with a baggage tractor, the driven force powering the acceleration of the tractor and luggage carts can be calculated using Newton's second law and kinematic equations to determine acceleration and speed over time.