The radius of curvature is smaller at the top than on the sides so that the downward centripetal acceleration at the top will be greater than the acceleration due to gravity, keeping the passengers pressed firmly into their seats. What is the speed of the roller coaster at the top of the loop (in m/s) if the radius of curvature there is 13.0 m and the downward acceleration of the car is 1.50 g?

Explanation:

The centripetal acceleration experimented by the roller coaster is:

The speed at the top of the loop is:

the answer is d

explanation:

dan realized that his goal of going to an ivy league school if only he works hard which means basically this   to become completely aware of (something) as a fact; understand without a doubt to make (something desired or anticipated) occur to give real, definite or physical form to a plan, dream, or goal to earn (money or a profit) from a deal

the answer is b, have negligible mass