thermodynamics

MECH 292 – Fall 2015

Ride 3: Power Tower

(+2 points)

Standing at 83.8 m tall, the “Power Tower” slowly hauls a platform of riders up to the top, then drops them in sudden freefall. Strong electromagnets kick in at 15.1 m above the ground, bringing the falling platform (m=2372 kg) to rest within just 2.3 s. The ride can also launch riders to the top from the bottom. To do so, the electromagnets rapidly accelerate the platform through the same 15.1 m within 1.9 s, then release the platform as a vertical projectile; at the top, the tower catches the rider platform just at the hang point. Relevant information is given in the diagram for A, B, C, D; use this information to answer the questions below.

1. Construct free body diagrams for the platform at A, B, C, D.

2. Find the minimum force of the electromagnets on the platform necessary to bring the riders to rest from freefall over 15.1 m, within 2.3 s.

3. Find the net acceleration (over 15.1 m, within 1.9 s) experienced by the riders when launched from the base of the tower to the top, so that the 2372 kg platform hangs at precisely 79 m above the ground.

4. Describe the sensation that riders would feel at A, B, C. Sustained exposure to accelerations greater than ~8g can cause even the most capable U.S. Air Force pilots to black out. What makes the accelerations felt by riders on the “Power Tower” safe?

Power Tower

1