Imagine a frictionless perfectly straight tunnel which runs from Boston (USA) to Delhi (India). We release (at zero speed) an object in the tunnel in Boston. Assume that the Earth is a perfect sphere with radius 6.4*10^3 km, with a mass of 6.0*10^24 kg and that the mass density is uniformly distributed throughout the Earth.
Question: How much time will it take the object to reach Delhi and what will be its speed when it gets to Delhi (3% accuracy is required)? You should ignore friction due to air-drag.