A gymnast jumps upward with an initial speed of 10 m/s. She is in the air for a total time of
A) 1 second
B) 5 seconds
C) 2 seconds
D) 10 seconds

Question

Quizplus · Accepted Answer

The total time a projectile (in this case, the gymnast) is in the air can be calculated using the formula $t = \frac{2v\sin(\theta)}{g}$, where $v$ is the initial velocity, $\theta$ is the launch angle, and $g$ is the acceleration due to gravity. Assuming the gymnast jumps vertically ($\theta = 90^\circ$, so $\sin(90^\circ) = 1$), and using $g = 9.8 \, \text{m/s}^2$, the time in air is $t = \frac{2 \times 10}{9.8} \approx 2$ seconds.

A Gymnast Jumps Upward with an Initial Speed of 10