She pushes off the floor with her legs and accelerates upward from rest to gain an upward velocity. Let’s assume she pushes for a 0.10 m distance, the approximate length of her (frog) legs.
When her legs no longer touch the floor, she has gained enough upward velocity so that she may travel another 1.2 meters in “free fall” (accelerating downward) to the top of the dresser where she lands approximately at rest.
Problem:
a.) Draw a force diagram of Tiana while she is pushing off and in contact with the floor. Label each force with a phrase that describes what is exerting the force and what is feeling the force (for example: Jada pushes on the book).
b.) Newton’s third law says for every action there is an equal and opposite reaction. Consider the force that is acting on Tiana in the upward direction. What is the reaction force to this one? What is that force exerted on?
c.) Assuming Tiana has a mass of 0.050 kg, how large is the force she must exert on the ground to propel her to the top of the dresser? Hint: This problem involves a few sub-problems. In one of the sub-problems, you will need to determine how fast she is going when her legs no longer touch the ground. There is no need to measure time in this video.
d.) How many times larger is the force in part c compared to her weight.