DO Drying of seedpods in some plants causes the seeds to be "fired" into the air. When each seed is at the top of its trajectory, which of the following statements about the nett force acting on it is true? (Ignore air resistance.) 1. Nett force acts vertically downwards. 2. Nett force is directed upwards. 3. Nett force changes direction at this instant. 4. Nett force is zero