Physics 1A

A 5 kg ball takes 26.8 seconds for one revolution around the circle.
What’s the magnitude of the angular velocity of this motion?
An automobile tire turns at a rate of 10 full revolutions per second and
results in a forward linear velocity of 19.8 m/s. What is the radius of the
tire?
An automobile with 0.248-m radius tires travels 80,000 km before the
tires need to be replaced. How many revolutions do the tires make in
this lifetime? Neglect any change in radius due to wear.
What is the angular speed of the hour hand of a 12-hour clock? Give
your answer in units of milliradians per second (abbreviated mrad/s).
Provide 3 digits of precision. Note that 1000 mrad = 1 rad.
Sarah and Tom are riding on a merry-go-round revolving at a constant
rate. Sarah is sitting at the outer edge of the merry-go-round and Tom
is half way in from the edge. Which of the following is true?
Earth turns on its axis about once every 24 hours. The Earth’s
equatorial radius is 6.38 x 106 m. If the Earth were to suddenly stop
spinning about its axis, with what speed would Earth’s inhabitants who
live at the equator initially “fly away” from their surroundings?
Which physics quantity is directly related to the tendency of an object
to maintain its state of motion?
Select the correct answer
Acceleration
Mass
Position
Velocity
Force
A 67.2-kg sprinter starts a race with an acceleration of 4.85m/s2
What is the net external force on him?
During each heartbeat, about 80 g of blood is pumped into the aorta
in approximately 0.20 s. During this time, the blood is accelerated
from rest to about 1.0 cm/s. What is the average net force on the
blood during this time?
[For this problem, treat the blood volume of blood that is moved from
the heart to the aorta as a solid mass, neglecting deformation, and
turbulence]
A 8.81 kg block is placed at the top of a frictionless inclined plane
angled at 20.4 degrees relative to the horizontal. When released (from
rest), the block slides down the full 3.45 meter length of the incline.
Calculate the speed (magnitude of the velocity) of the block at the
bottom of the incline. [Start by drawing a free-body diagram for the
block.] Note that all the information provided may not be necessary to
solve the problem.