A skater pushes off with one foot and then glides in a circle. Is a net force acting on the skater? How can you tell?
Yes, the inside or outside edge of the blade exerts a force. That is what keeps the skater changing direction and moving in a circle.
To determine if a net force is acting on the skater, we would need to examine the concept of net force and the motion of the skater.
Net force refers to the overall force acting on an object, taking into account both the magnitude and direction of the individual forces. If the net force on an object is non-zero, it will result in the object's acceleration or a change in its motion.
In the given scenario, when the skater pushes off with one foot, they generate a force in one direction. As a result, the skater starts moving in a circular path, undergoing circular motion.
During circular motion, an object continually changes its direction, even if its speed remains constant. This change in direction indicates that an inward force, called centripetal force, must be acting on the skater. In this case, the centripetal force is provided by the friction between the skater's skate and the ground.
Now, if we consider the skater's net force, we find that there are two forces acting on the skater: the force generated by the skater's push and the force of friction providing the centripetal force. These forces cancel each other out, and since the acceleration is zero (constant speed in a circular path), we can conclude that the net force acting on the skater is zero.
In summary, in the scenario described, due to the presence of two equal and opposite forces (push and friction) producing balanced motion, the net force on the skater is zero.