When you apply a constant force to an object does the object move at a constant velocity or does it’s velocity increase? Explain why this occurs using your understanding of acceleration/force (gravity)
When a constant force is applied to an object, its velocity can either remain constant or change. It depends on the overall force acting on the object and how it balances with other forces. Let's investigate this using the concepts of acceleration, force, and gravity.
Newton's second law of motion states that the acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass. Mathematically, it can be expressed as:
a = F/m
Where:
a = acceleration
F = net force acting on the object
m = mass of the object
Gravity exerts a force on most objects near the Earth's surface. The force due to gravity is known as the weight of the object and can be calculated by multiplying its mass (m) by the acceleration due to gravity (g), which is approximately 9.8 m/s².
Now, let's consider two scenarios:
1. Initial velocity is zero: If an object initially at rest experiences a constant force in the same direction, it will accelerate according to Newton's second law. The force applied will be greater than the opposing force of friction or air resistance, causing the object to accelerate. Its velocity will increase over time until it reaches a point where the net force equals the opposing force(s). At this point, the object will move at a constant velocity since acceleration is zero (a = 0).
2. Initial velocity is not zero: If an object is already moving with a constant velocity and a constant force is applied in the same direction, it will continue moving at the same velocity. This occurs when the applied force exactly counterbalances the opposing forces, such as friction or air resistance. In this case, there is no net force acting on the object, and therefore, no acceleration. Consequently, the object will maintain a constant velocity.
However, it's important to note that if the applied force is greater than the opposing forces (such as when continuously pushing an object with a force exceeding friction), then the object will continue to accelerate and its velocity will increase further.
In summary, whether an object's velocity remains constant or increases when a constant force is applied depends on the balance between the applied force and opposing forces. If the applied force is equal to the opposing forces, the object will move at a constant velocity. If the applied force exceeds the opposing forces, the object will accelerate, and its velocity will increase over time.