Questions: Which situations are modeled accurately by a periodic
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function? Select all that apply.
the height of a ball tossed in the air as a function of time
the vertical height of a point on a rotating wheel as a function of time
the height of a swinging pendulum as a function of time
the distance from the earth to the moon as a function of time
Transcript text: Which situations are modeled accurately by a periodic
22
function? Select all that apply.
the height of a ball tossed in the air as a function of time
the vertical height of a point on a rotating wheel as a function of time
the height of a swinging pendulum as a function of time
the distance from the earth to the moon as a function of time
Solution
Solution Steps
To determine which situations are modeled accurately by a periodic function, we need to identify scenarios where the behavior repeats at regular intervals. A periodic function is one that repeats its values in regular intervals or periods.
The height of a ball tossed in the air as a function of time is not periodic because the ball follows a parabolic trajectory and does not repeat its motion in a regular cycle.
The vertical height of a point on a rotating wheel as a function of time is periodic because the wheel rotates in a circle, repeating its position at regular intervals.
The height of a swinging pendulum as a function of time is periodic because the pendulum swings back and forth in a regular, repeating cycle.
The distance from the earth to the moon as a function of time is not strictly periodic because it varies due to the elliptical orbit and other gravitational influences, though it may have periodic components.
Step 1: Identify Periodic Functions
To determine which situations are modeled accurately by a periodic function, we analyze each scenario for regularity in their behavior over time.
Step 2: Analyze Each Situation
Height of a ball tossed in the air: This follows a parabolic trajectory, described by \( h(t) = -gt^2 + v_0t + h_0 \), where \( g \) is the acceleration due to gravity, \( v_0 \) is the initial velocity, and \( h_0 \) is the initial height. This function is not periodic.
Vertical height of a point on a rotating wheel: This can be modeled by a sine function, \( h(t) = r \sin(\omega t + \phi) \), where \( r \) is the radius, \( \omega \) is the angular velocity, and \( \phi \) is the phase shift. This function is periodic with period \( T = \frac{2\pi}{\omega} \).
Height of a swinging pendulum: The height can also be modeled by a sine function, similar to the rotating wheel, \( h(t) = A \sin(\omega t + \phi) \), where \( A \) is the amplitude. This function is periodic with period \( T = \frac{2\pi}{\omega} \).
Distance from the Earth to the Moon: This distance varies due to the elliptical orbit and is not periodic in a strict sense, as it does not repeat in a regular cycle.
Step 3: Compile Results
From the analysis, the situations that are periodic are:
The vertical height of a point on a rotating wheel as a function of time.
The height of a swinging pendulum as a function of time.
Final Answer
The answer is: \\(\boxed{\text{the vertical height of a point on a rotating wheel and the height of a swinging pendulum}}\\).