Peggy is runnig around the school track at a constant speed. The track has two straight stretches on the sides and two curved stretches at either end. Where on the track does Peggy experience balanced and unbalanced forces? Explain your answer.

To understand where Peggy experiences balanced and unbalanced forces while running on the school track, we need to consider the forces acting on her and how they change throughout her run.

1. Straight stretches:
During the straight stretches of the track, Peggy experiences balanced forces. When she runs at a constant speed, her acceleration is zero, which indicates that the net force acting on her is also zero. This means that the forces pushing her forward (such as her leg muscles propelling her) are equal and opposite to the forces resisting her motion (such as air resistance and friction between her feet and the ground). As a result, the net force on Peggy is balanced, and she continues to move at a constant speed in a straight line.

2. Curved stretches:
When Peggy reaches the curved stretches of the track, she experiences unbalanced forces. As she turns around the curved sections, her velocity changes direction, which means she is accelerating. According to Newton's first law of motion, an object will accelerate when an unbalanced force acts upon it. In this case, the inward force responsible for this acceleration is the centripetal force, which keeps Peggy moving in a curved path along the track. This centripetal force is exerted by the friction between Peggy's feet and the ground, enabling her to maintain the curved path without slipping or sliding off the track.

It is important to note that the direction of the net force on Peggy is constantly changing as she moves along the track. On the straight stretches, the net force is balanced, whereas on the curved stretches, it becomes unbalanced due to the need for centripetal force to maintain the curved motion.