What are precautions to take when doing a practical experiment of Newton's second law?
Newton's Second Law of Motion deals with unbalanced forces; the acceleration of an object is related to the mass of the object and the force applied to it, or F=ma. Experiments done that involve this principle frequently involve the use of gravity or rockets as the accelerating force, and some type of weight as the mass. Without knowing what specific experiments you are doing it is difficult to list specifics, but the usual safety precautions in experiments that can involve projectiles are those related to keeping eyes and other body parts safe from various types of impact. Safety goggles should be worn due to the chance of an object accelerating into someone's face. The quality of all equipment should be checked; boards and strings are frequently used, and if they break the weights can impact fingers and feet. Bubble wrap is sometimes used in the area where a weight impacts the floor. Breakable objects should be removed from the immediate area. Although not always listed as a precaution, rules for safe student behavior should always be followed, and only the planned experiments performed.