Question

Amelia is riding the Giant Drop at Great America. If she free falls for 3.45 seconds, what

will be her final velocity and displacement?
0 33.8m/s & -58.3m
33.8m/s & 58.3m
34m/s & 58m
33.8m/s & 58.3m

Answer 1

-33.8 m/s & -58.3 m

Step-by-step explanation:

We have two known variables from the start: acceleration and time. Since Amelia is in free-fall, the acceleration is due to gravity (g = 9.8 m/s²). We want to find her final velocity and displacement after 3.45 seconds.

Let's start by finding displacement assuming her final velocity is -33.8 m/s.

Using this kinematic equation:

• Δx = vt - 1/2at²

Substitute the known variables into the equation. Assuming the downwards direction is negative:

• Δx = (-33.8)(3.45) - 1/2(-9.8)(3.45)²
• Δx = -116.61 + 58.32225
• Δx = -58.28775

If Amelia's final velocity is -33.8 m/s, then her displacement is -58.3 m.

This eliminates the second and fourth choice, because the displacement would not match up with her final velocity.

The third choice does not make sense because if her final velocity was negative, her displacement would not be positive.

Therefore, the correct answer is choice A: -33.8 m/s & -58.3 m.