An object of mass 0.20 kg is connected by a string to an object of half its mass. The
smaller mass is rotating at a radius of 0.15 m on a table which has a frictionless surface.
The larger mass is suspended through a hole in the middle of the table.
Calculate the number of revolutions per minute the smaller mass must make so that the larger mass is stationary?
how to answer this question?
During trial firing of Pioneer Moon rockets, one rocket reached an altitude of
125,000 km. Neglecting the effect of the Moon, estimate the velocity with which this
rocket struck the atmosphere of the Earth on its return. (Assume that the rocket’s path is
entirely radial and that the atmosphere extends to a height of 130 km above the Earth
Please don't answer this, I just need a direction of what theory should I think about here and how to approach this question, I think they are talking about impact velocity but that is not mentioned in the curriculum.