Final answer:
The statement about people having the same proportion of muscle fiber types is false; the heart is made up of cardiac muscle, not smooth muscle, making that statement also false; sprinting is correctly categorized as an anaerobic exercise, which is true; and a position vs time graph for an object speeding up is not a straight line, which is false.
Step-by-step explanation:
When examining the statement "All people have the same proportion of slow-twitch to fast-twitch muscle fibers," it is important to recognize the individual variability in muscle fiber composition. The answer to this statement is False. Humans possess a mix of both slow-twitch (type I) and fast-twitch (type II) muscle fibers, but the proportion between them varies from person to person based on genetics, training, and other factors.
Regarding the human heart, it is composed of a specialized type of muscle known as cardiac muscle, not smooth muscle. Therefore, the statement "The heart consists of smooth muscle tissue" is also False.
When considering exercises and their categorization, sprinting is a high-intensity, short-duration activity that relies on anaerobic energy systems due to the lack of oxygen being provided for the duration of the sprint. Thus, the statement "Sprinting is considered an anaerobic exercise" is True.
Finally, addressing the topic of physics, the position vs time graph for an object that is speeding up will not be a straight line. Instead, this graph will show a curve that gets steeper as time progresses, indicating increasing velocity. The correct answer is False for the statement "The position vs time graph of an object that is speeding up is a straight line."