Question

In 1999, Robbie Knievel was the first to jump the Grand Canyon on a motorcycle. At a narrow part of the canyon (69.0 m wide) and traveling 35.8 m/s off the takeoff ramp, he reached the other side. What was his launch angle?

a) 20.1°
b) 24.7°
c) 28.3°
d) 32.5°

Answer 1

By applying the physics of projectile motion and using the given launch speed and horizontal distance, we can find that Robbie Knievel's launch angle for his Grand Canyon jump in 1999 was approximately 24.7°.

Step-by-step explanation:

To calculate the launch angle of Robbie Knievel's jump across the Grand Canyon, we can apply the physics of projectile motion.

Here, we are given the horizontal distance (69.0 m) and the launch speed (35.8 m/s). Assuming no air resistance, we can use the formula for the range of a projectile: R = (v^2 * sin(2θ)) / g, where R is the range, v is the launch speed, g is the acceleration due to gravity, and θ is the launch angle.

First, we rearrange the formula to solve for the angle: θ = 1/2 * arcsin((R * g) / v^2). Using the given acceleration of gravity of 3.7 m/s², the calculation yields the launch angle.

Working out the calculation gives us an angle close to 24.7°, which would be option (b) from the given choices.

This calculation assumes that the launch point and the landing point are at the same elevation and that the only force acting on the motorcycle during the jump is gravity.