When does a roller coaster have the most kinetic energy

In the image, the arrow is pointing to a celestial object. which attribute disqualifies the object from being a planet?

2.22/3.33 points | previous answers tamucolphysmechl1 4.pre.002. ask your teacher my notes question part points submissions used on a frictionless air track, a blue glider with mass 0.200 kg is moving to the right with a speed of 8.00 m/s. it strikes a red glider that has mass 0.600 kg and that is initially at rest. after the collision, the blue glider is moving to the left with a speed of 2.40 m/s. (a) what are the magnitude and direction of the velocity of the red glider after the collision? magnitude 3.33 m/s correct: your answer is correct. direction correct: your answer is correct. (b) is this collision elastic?

Consider a uniformly charged ring in the xy plane, centered at the origin. the ring has radius a and positive charge qdistributed evenly along its circumference. a)what is the direction of the electric field at any point on the z axis? . b)what is the magnitude of the electric field along the positive z axis? use k in your answer, where k=14πϵ0. d)the ball will oscillate along the z axis between z=d and z=−d in simple harmonic motion. what will be the angular frequency ω of these oscillations? use the approximation d≪a to simplify your calculation; that is, assume that d2+a2≈a2. express your answer in terms of given charges, dimensions, and constants