Your starship lands on a mysterious planet. as chief scientist-engineer, you make the following measurements: a 2.50-kg stone thrown upward from the ground at 12.0 m/s returns to the ground in 6.00 s; the circumference of the mysterious planetat the equator is 2 ×10okm; and there is no appreciable atmosphere. the starship commander asks for the following information: (a) what is the mass of this mysterious planet? (b) if the starship goes into a circular orbit 30,000 km above the surface of the planet, how many hours will it take the ship to complete one orbit?

We put a force of 50n on an object and the acceleration is 100 m/s². what is the mass of the object?

The material that keeps its new shape after it is stretched is called?

In an old-fashioned amusement park ride, passengers stand inside a 3.0-m-tall, 5.0-m-diameter hollow steel cylinder with their backs against the wall. the cylinder begins to rotate about a vertical axis. then the floor on which the passengers are standing suddenly drops away! if all goes well, the passengers will “stick” to the wall and not slide. clothing has a static coefficient of friction against steel in the range 0.60 to 1.0 and a kinetic coefficient in the range 0.40 to 0.70. part a what is the minimum rotational frequency, in rpm, for which the ride is safe? express your answer using two significant figures. f f = rpm