you push a large box across the floor at a constant velocity of 3m/s. a)what is the net force on the box? b)what forces act on the puck?
(a) the net force is zero (see 1 Newton"s law)
(b) gravity and normal force
a) When an object is moving at a constant velocity, it means that the net force acting on it is zero. This is because the forces opposing its motion are balanced by the applied force. Therefore, in this case, the net force on the box would be zero.
b) There are typically two main forces acting on the box when it is pushed across the floor:
1. Applied force: This is the force which is pushing the box forward. In this case, it is the force applied by you to move the box. Since the box is moving at a constant velocity, the applied force must be exactly equal in magnitude and opposite in direction to the forces opposing its motion.
2. Frictional force: This force opposes the motion of the box and is caused by the interaction between the box and the surface it is sliding on. In this case, as the box is being pushed across the floor, the frictional force would be equal in magnitude and opposite in direction to the applied force. This ensures that the net force is zero, resulting in the constant velocity.
To answer these questions, we need to understand the concept of force and the forces acting on an object. Let's break it down step by step:
a) What is the net force on the box?
To determine the net force on an object, we need to understand Newton's first law, also known as the law of inertia. It states that an object at rest or moving with constant velocity will continue to do so unless acted upon by an external force.
In this case, since the box is moving with a constant velocity of 3 m/s, we can assume that the net force acting on the box is zero. This means that all the forces acting on the box are balanced, resulting in no acceleration.
b) What forces act on the box?
When pushing a box, you are applying a force to overcome the friction between the box and the floor. There are typically two main forces acting on the box:
1. Applied force: This is the force you are exerting while pushing the box. It is directed in the direction in which the box is being pushed, which is horizontally in this case. The magnitude of the applied force depends on the strength with which you push the box.
2. Frictional force: This force opposes the motion of the box and is exerted by the surface it is sliding on. The frictional force acts in the opposite direction to the applied force. In this case, since the box is moving at a constant velocity, the frictional force must be equal in magnitude and opposite in direction to the applied force. If it were larger, the box would decelerate, and if it were smaller, the box would accelerate.
It's worth noting that there might be other negligible forces present, such as air resistance, but in this scenario, we are assuming they are negligible since they are not mentioned.
To summarize, when you push the large box across the floor at a constant velocity of 3 m/s, the net force on the box is zero, and the main forces acting on the box are the applied force and the frictional force.