Exercises 23, 24, 25, 26, and 27 describe a situation. For each, identify all forces acting on the object and draw a free-body diagram of the object. An ice hockey puck glides across frictionless ice.

Verified step by step guidance

1. Identify the object in question: In this scenario, the object is an ice hockey puck.
2. List all forces acting on the puck: Since the puck is on frictionless ice, the primary forces to consider are the gravitational force acting downward and the normal force exerted by the ice acting upward.
3. Consider any additional forces: If the puck is moving, it might have been set into motion by an initial force (like being hit by a stick), but no additional forces act on it once it's gliding, except if there's air resistance which is usually negligible in such scenarios.
4. Draw the free-body diagram: Place a dot to represent the puck. Draw an arrow pointing downward from the center of the dot, labeling it as the gravitational force (mg, where m is the mass of the puck and g is the acceleration due to gravity). Draw another arrow of equal length pointing upward from the center of the dot, labeling it as the normal force (N).
5. Analyze the motion: Since the puck is moving on frictionless ice, the horizontal forces are balanced (if considering any initial force has ceased after setting the puck in motion), and the vertical forces are also balanced (normal force equals gravitational force). This results in no net force acting on the puck, allowing it to glide smoothly across the ice.

Key Concepts

Free-Body Diagram

A free-body diagram is a graphical representation used to visualize the forces acting on an object. It typically includes the object in question, with arrows indicating the direction and magnitude of each force. This tool helps in analyzing the net force and understanding the motion of the object based on Newton's laws.

Forces

Forces are interactions that can cause an object to accelerate, change direction, or deform. In the context of the hockey puck, the primary forces to consider are gravitational force acting downward and the normal force acting upward from the ice surface. Since the ice is frictionless, there are no frictional forces opposing the puck's motion.

Newton's First Law of Motion

Newton's First Law states that an object at rest will remain at rest, and an object in motion will continue in motion with the same speed and in the same direction unless acted upon by a net external force. This principle is crucial for understanding the behavior of the hockey puck as it glides across the ice, indicating that it will maintain its state of motion until a force, such as friction or a collision, acts on it.