The force that the book exerts on the table is a normal force, not a weight force. (The book's weight doesn't act on the table, it acts on the book.) It's equal in magnitude to the weight of the book, again, because of the first law.
Answer:

Explanation:
The roller coaster begins with maximum kinetic energy and no gravitational potential energy. The gravitational potential energy reaches its maximum when roller coaster is upside down at the top of the circle. The physical model for the roller coaster is constructed by means of the Principle of Energy Conservation:

The minimum velocity is:

Let assume that radio of curvature is measured in meters. Hence:


Answer:
The height reached by the material on Earth is 91 km.
Explanation:
Given that,
Mass 
Radius = 1821 km
Height 
Suppose we need to find that how high would this material go on earth if it were ejected with the same speed as on Io?
We need to calculate the acceleration due to gravity on Io
Using formula of gravity

Put the value into the formula


Let v be the speed at which the material is ejected.
We need to calculate the height
Using the formula of height

Using ratio of height of earth and height of Io


Put the value into the formula





Hence, The height reached by the material on Earth is 91 km.
Answer:
192.5 miles
Explanation:
55mph = 55 miles in 1 hour
55 X 3.5 = 192.5