1. Two point masses m and M are separated by a distance d. If the distance between the masses is decreased to one-third (1/3) d, how does the gravitational force between them change?

2.

A ball is whirled on the end of a string in a horizontal circle of radius R at speed v. By which one of the following means can the centripetal acceleration of the ball be increased by a factor of four? O Keep the speed fixed and decrease the radius by a factor of two. O Keep the radius fixed and increase the period by a factor of two. O Keep the radius fixed and decrease the period by a factor of two. O Keep the speed fixed and increase the radius by a factor of two. O Keep the radius fixed and increase the speed by a factor of four.Consider a hypothetical planet in our solar system whose average distance from the Sun is about nine times that of Earth. Determine the orbital period for this hypothetical planet. O 8 years O 0.25 year O 16 years O 27 years O 4 yearsThe apparent weight of a passenger in an elevator is smaller than his tme weight. Which one of the following is true? ID The elevator is moving upward with a decreasing speed or downward with an increasing speed 1:) The elevator is moving upward with an increasing speed or moving downward with an decreasing speed C) The elevator is moving upward with an increasing speed or moving upward with an increasing speed ID The elevator is moving upward with an increasing speed or moving downward with a constant speed C) The elevator is moving upward with a constant speed or downward with a constant speed We have to get. a = Lev R . T = 20 - a = 4ac . ac = 1 T / R for option ( 2 ) ar = An R 2 Radius fixed ie . R fixed . period is increased by 2 le . T'= 2T . . . a from 417 R ac = a = AT1 R T ' ace T '2 ac ac = ac i -e. acceleration is decreased by ac 4 factor 9 . for option 3) Radius is fixed je . R fixed . Period decreased by factor 2. ie . Th= ac ac ac 4 gac = ac Aus