Which situation best represents a closed environment? two balls colliding on a pool table

two balls colliding in midair

two balls colliding in deep space

two balls colliding under water

Your pendulum clock which advances 1.0 s for every complete oscillation of the pendulum is running perfectly on earth at a site where the magnitude of the acceleration due to gravity is 9.80 m/s2. you send the clock to a location on the moon where the magnitude of the acceleration due to gravity is 1.65 m/s2.

Three different objects, all with different masses, are initially at rest at the bottom of a set of steps. each step is of uniform height . the mass of each object is a multiple of the base mass : object 1 has mass 4..00m , object 2 has mass 1..96m , and object 3 has mass . when the objects are at the bottom of the steps, define the total gravitational potential energy of the three-object system to be zero. if the objects are then relocated as shown, what is the new total potential energy of the system? each answer requires the numerical coefficient to an algebraic expression. each algebraic expression is given using some combination of the variables , , and , where is the acceleration due to gravity. enter only the numerical coefficient. (example: if the answer is 1..23mgd , just enter 1.23)

What is the weight of a feather (mass = 0.0001 kg) that floats through earth's and the moon's atmospheres?