Journals

SPRING PHYSICS 2017

Journal #1 1/12/20171. During the spin cycle of a washing machine, the clothes

stick to the outer wall of the barrel as it spins. If the radius of the barrel is 0.260 m and the time for one revolution is 0.0330 s, how fast is the barrel spinning?

49.5 m/s

2. A battery-powered plane is suspended from a string and flying in a horizontal circle. The plane makes a complete circle every 2.15 seconds. The radius of the circle is 0.950 m. If the plane has a mass of 0.631 kg determine the centripetal force acting on the plane.

5.12 N

DO NOT ROUND UNTIL THE END.

Journal #2 1/13/20171. A 45 kg merry-go-round worker stands 6.3 m from

the center of the ride and it takes 9.65 s for the ride to make one revolution.

A. What is the centripetal force acting on the worker?

120 N

B. What type of force provides the centripetal force?

friction

Journal #3 1/17/20171. Determine the force of gravitational attraction between the

earth (m = 5.98 x 1024 kg) and a 70.0 kg physics student if the student is in an airplane at 40000 feet above earth's surface. This would place the student a distance of 6.39 x 106 m from earth's center.

684 N

2. Suppose that two objects attract each other with a gravitational force of 40N. If the distance between the two objects is doubled, what is the new force of attraction between the two objects?

10 N