Communications satellites are placed in a circular orbit where they stay directly over a fixed point on the equator as the earth rotates. These are called geosynchronous orbits. The altitude of a geosynchronous orbit is 3.58 x 107 m ( 22,000 miles). Correct ▼ Part B ▼ Find the value of g at this altitude. Express your answer with the appropriate units. ►View Available Hint(s) HÅ 9= 0.2242 Submit Previous Answers Part C W = 0 What is the weight of a 2000 kg satellite in a geosynchronous orbit? Express your answer with the appropriate units. View Available Hint(s) O m sec² HÅ 6.0 p ? g w ?

1. Gravity: a. What is the magnitude and direction of the gravitational force that the Earth exerts on you in Sl units? Make a reasonable numerical estimate and include units. b. The SI unit of force is a newton. What is a newton in terms of the more basic units, kilograms (kg), meters (m), and seconds (sec)? What is the magnitude and direction of the gravitational force that you exert on the Earth? Consider your answer to part a. 2. Contact Forces¹: Besides gravity, nearly all other forces we will encounter in this course are contact forces, which means that the two objects must be touching for the objects to exert forces on each other. Normal Force: When a surface is touching an object, the surface exerts a force on the object that is perpendicular to the surface and pushes into the object. This is called a "normal" force (normal means perpendicular in math). The harder the surfaces press against each other, the larger the normal force.²

Two identical stars with mass M orbit around their center of mass. Each orbit is circular and has radius R, so that the two stars are always on opposite sides of the circle. Part A Find the gravitational force of one star on the other. Express your answer in terms of G, M, R. Πν ΑΣφ ? F = Part B Find the orbital speed of each star. Express your answer in terms of G, M, R. να ΑΣΦ7 ? Part C

You are given the equation used to solve a problem: (6.67 × 10-¹¹N m²/kg²)(5.98 × 10²4 kg)(1000 kg) p2 Part A Choose the correct realistic problem for which this is the correct equation. Submit A 1000 kg comet falls on the earth with a speed of 1997 m/s when it reaches the surface. What was the radius of its orbit? A 1000 kg satellite orbits Saturn with a speed of 1997 m/s. What is the radius of the orbit? A 1000 kg satellite orbits the earth with a speed of 1997 m/s. What is the radius of the orbit? A 1000 kg comet falls on Saturn with a speed of 1997 m/s when it reaches the surface. What was the radius of its orbit? Part B r = Previous Answers Correct Finish the solution of the problem. Express your answer with the appropriate units. (1000 kg) (1997 m/s)² p C'H μA Value Units ?