4- An object weighs 30 newtons on Earth. What is its approximate mass? SHOW YOUR WORK.

15 In Vienna, there is a Ferris wheel designed so that the passengers ride in a standing position. If one of the passengers were standing on a bathroom scale while the ride rotated at a constant speed, the scale would read lowest at

the point in the ride where they were descending most rapidly

the point in the ride where they were ascending most rapidly.

the highest point in the ride.

the lowest point in the ride.

16- In his model of the motions of the planets, Copernicus

was able to make predictions that were much more accurate than Ptolemy's model.

found that the planets move in paths shaped like ellipses.

revived the idea that our solar system is heliocentric (Sun-centered).

assumed that the Earth is the center of the solar system.

19 The maximum acceleration a pilot can stand is about 7.0 g. What is the minimum radius of curvature that a jet plane's pilot, pulling out of a vertical dive, can tolerate at a speed of 250 m/s?

20 What is the gravitational force on a 70. kg person on the Earth, due to the moon? The mass of the moon is 7.36 x 10^22 kg and the distance to the moon is 3.82 10^8m