A truck in driving up the interstate with a constant velocity. Is work being done by a net external force acting on the truck? Justify answer. Why doesn't the work done by the engine pushing it forward make its kenetic energy increase?
The truck is moving at constant velocity - means zero acceleration - that can happen only when the net force acting on the truck is zero.The frictional force opposes the motion and its magnitude is same as that produced by the engine for forward motion (under constant velocity condition).
Since the net force is zero, the work done by it is zero.
The KE of the truck does not increase because the truck is moving at constant velocity. Yet the truck's engine is delivering power that is just sufficient to compensate for the loss of energy due to frictional forces.
Well, that's a truckload of questions! Let's drive straight into it.
First off, if the truck is traveling with a constant velocity on the interstate, that means there is no change in its speed or direction. In this case, no net external force is required to keep the truck moving at a constant velocity. So, the work done by the net external force would be zero.
Now, let's talk about the engine and why it doesn't increase the truck's kinetic energy. When the engine pushes the truck forward, it does indeed do work on the truck. However, the work done by the engine is canceled out by the opposing forces acting on the truck, such as friction and air resistance.
Since the work done by these opposing forces is equal in magnitude and opposite in direction to the work done by the engine, the net work done on the truck is also zero. And according to good ol' physics, if the net work done on an object is zero, then there's no change in its kinetic energy.
In simple terms, the truck's kinetic energy isn't increasing because the engine's work is being offset by the truck's encounters with opposing forces. It's like trying to make a sandwich with equal amounts of peanut butter and jelly - they cancel each other out, leaving you with a delicious equilibrium.
So, in conclusion, despite the engine's efforts, the truck's kinetic energy remains constant because the external forces acting on it balance out the work done by the engine. Keep on truckin' with your physics questions!
When a truck is driving up the interstate with a constant velocity, the net external force acting on the truck is zero. According to Newton's first law of motion, an object at rest or moving with a constant velocity will continue to do so unless acted upon by an external force.
Since the truck is maintaining a constant velocity, it means that the net external force acting on the truck is balanced, and therefore, no work is being done by any external force.
In the case of the engine pushing the truck forward, although the engine does work to provide the necessary force to overcome any frictional forces, air resistance, or the incline of the road, this work is countered by other forces acting on the truck. As a result, the net work done on the truck is still zero.
Even though the engine may be doing work, the work done by the engine does not directly cause an increase in the truck's kinetic energy. This is because the work done on an object is equal to the change in its kinetic energy, as given by the work-energy theorem. In this case, since the truck has a constant velocity, its kinetic energy remains unchanged.
Therefore, the work done by the net external force on the truck is zero, and the work done by the engine does not result in an increase in its kinetic energy due to the balancing forces acting on the truck.
To determine if work is being done by a net external force acting on the truck, we need to understand the concept of work and its relationship to velocity.
Work is defined as the transfer of energy that occurs when a force is applied to an object and it is displaced in the direction of the force. Mathematically, work (W) is calculated as the product of the force (F) acting on an object and the distance (d) over which the force is applied, multiplied by the cosine of the angle (θ) between the force and the displacement:
W = F * d * cos(θ)
In the given scenario, the truck is driving up the interstate with a constant velocity. When an object moves at a constant velocity, it means there is no net force acting on it, as there is no acceleration. Therefore, if there is no net external force acting on the truck, no work is being done on it.
Now, let's address the second part of your question. The engine of the truck is pushing it forward, supplying a force that propels the vehicle. However, even though the engine does work, it does not directly increase the truck's kinetic energy. This can be understood by considering the work-energy principle.
According to the work-energy principle, the work done on an object is equal to the change in its kinetic energy. In this case, since the truck is moving at a constant velocity, its kinetic energy remains constant. The work done by the engine is used to overcome various forms of resistance, such as friction and air resistance, which may decrease the truck's kinetic energy by dissipating it as heat or sound. Therefore, the work done by the engine is not solely responsible for increasing the truck's kinetic energy.
In summary, in the given scenario, no work is being done by a net external force acting on the truck since it is moving at a constant velocity. The work done by the engine pushing the truck forward is not directly responsible for an increase in the truck's kinetic energy, as the energy may be dissipated in overcoming various resistances.