Tangential speed of a building on equator of earth kr?

Identical marbles are released from the same height on each of the following four frictionless ramps . compare the speed of the marbles at the end of each ramp. explain your reasoning

When considering gravity acceleration and the force of acceleration, what must be true? a. the direction of acceleration must be perpendicular to the direction of the force. b. the direction of the force and the direction of acceleration must be the same as each other. c. the direction of the force and the direction of acceleration must be opposite of each other. d. the mass of the body must be the same as the acceleration of the body.

The discovery of the electron as a subatomic particle was a result of