Download U9 WS 2 - Rollercoasters

U9 WS 3 – Rollercoasters (Energy and Circular Motion)
NAME_________________________ Per__
Below is part of the track on a roller coaster ride that you are riding. You are in motion at all points A-H
B
1. A. If it takes 0.1 seconds for you to pass
through one meter of track at point B, how
fast are you going at point B? What
direction is your velocity at point B?
F
12m
A
C
G
D
6m
E
H
B. What size and in what direction is your acceleration at point B?
2. A. Calculate the net force on you at point B (your mass is 80 kg).
B. Draw a force diagram for you at point B. Calculate the size of all the
forces on you at point B and put these amounts on your force diagram.
3. A. If point B is 28 meters higher than point D, how fast must you be going at point D (Assume no energy is
dissipated between B and D)? (hint: think energy!)
B. Are you accelerating at point D? If so, in which direction and how much? ( Hint: figure out the radius.)
C. Draw a force diagram for you at point D. Calculate the size of all the
forces on you at point D and put these amounts on your force diagram.
4. Suppose you have enough speed to just make it past point F without falling
off the track.
A. Draw a force diagram to represent this situation.
B. Determine the minimum velocity needed to make it through the loop.
(Hint: use your force diagram)
C. Calculate your acceleration at point F.
5. A. How fast must you be going at point H, if 10 % of the energy you started with is dissipated during your
trip?
B. Draw a force diagram for you at point H.
6. Sally has a mass of 40 kg. She rides the Ferris
wheel as the wheel rotates at a constant speed. She uses her
fancy wristwatch to determine that it takes 12.57 seconds for
her to make a complete trip around the wheel.
r = 4.5 m
A
A. Determine the speed and acceleration of Sally at any point
on the wheel.
C
B
B. Force diagrams:
Draw quantitative force diagrams -- one for the net force, one for the individual forces -- for Sally at the
three locations.
A.
B.
C.
Force Diagram
Force Diagram
Force Diagram
Net Force Diagram
Net Force Diagram
Net Force Diagram
7. At what constant speed would the 80 kg driver pictured below have to be
traveling in order to feel twice his normal body weight as he drives into a
depression in the road with a radius of curvature of 20 meters.
Be sure to draw a force diagram to represent the situation before you even
attempt to solve the problem. Hint: which force affects how much weight you
feel that you have?
r = 20m