Question

A street performer tosses a ball straight up into the air (event 1 ) and then catches it in his mouth (event 2 ). For each of the following observers, state whether the time they measure between these two events is the proper time or the dilated time: (a) the street performer; (b) a stationary observer on the other side of the street; (c) a person sitting at home watching the performance on TV (d) a person observing the performance from a moving car.

Answer 1

The correct answer is C).The street performer and the stationary observer measure the proper time for the ball toss event, while the observer in a moving car would measure dilated time if their speed were significant. Observers watching on TV are subject to broadcast delays, not relativistic effects.

Step-by-step explanation:

The concept of proper time and time dilation is rooted in the theory of relativity, which concerns the measurement of time intervals between events as observed from different frames of reference. For the street performer tossing a ball and catching it, we can determine if each observer measures the proper time or the dilated time:

• (a) The street performer measures the proper time, as he is at rest relative to the event.
• (b) A stationary observer across the street also measures the proper time because they are stationary relative to the event happening on their side of the street.
• (c) A person sitting at home watching on TV measures neither proper nor dilated time directly; the broadcast signal transmission introduces a delay unrelated to time dilation.
• (d) A person observing from a moving car measures dilated time if their velocity relative to the event is significant, which is unlikely at typical urban driving speeds.

According to relativity, proper time is measured by an observer who is at rest relative to the event, while time dilation affects moving observers.