College Physics Problem 2.28

A powerful motorcycle can accelerate from rest to 26.8 m/s (100 km/h) in only 3.90 s.
(a) What is its average acceleration?
(b) How far does it travel in that time? Continue reading “College Physics Problem 2.28”

College Physics Problem 2.26

Blood is accelerated from rest to 30.0 cm/s in a distance of 1.80 cm by the left ventricle of the heart.
(a) Make a sketch of the solution.
(b) List the knowns in this problem.
(c) How long does the acceleration take? To solve this part, first identify the unknown, and then discuss how you chose the appropriate equation to solve for it. After choosing the equation, show your steps in solving for the unknown, checking your units.
(d) Is the answer reasonable when compared with the time for a heartbeat?

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College Physics Problem 2.17

Dr. John Paul Stapp was U.S. Air Force officer who studied the effects of extreme deceleration on the human body. On December 10, 1954, Stapp rode a rocket sled, accelerating from rest to a top speed of 282 m/s (1015 km/h) in 5.00 s, and was brought jarringly back to rest in only 1.40 s! Calculate his
(a) acceleration and
(b) deceleration.
Express each in multiples of g\:\left(9.80\:\right)m/s^{2} by taking its ratio to the acceleration of gravity.

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College Physics Problem 2.15

The planetary model of the atom pictures electrons orbiting the atomic nucleus much as planets orbit the Sun. In this model, you can view hydrogen, the simplest atom, as having a single electron in a circular orbit 1.06\times 10^{-10}\:m in diameter.
(a) If the average speed of the electron in this orbit is known to be 2.20\times 10^6\:m/s, calculate the number of revolutions per second it makes about the nucleus.
(b) What is the electron’s average velocity?

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