A 45 kg puggle and a 130 kg puma are at a standoff (staring at each other) with a distance 70 m between them. What is the magnitude of the force of gravity between the puggle and the puma?

What is the role of lenses in microscopy?

At 20∘c, the hole in an aluminum ring is 2.800 cm in diameter. you need to slip this ring over a steel shaft that has a room-temperature diameter of 2.804 cm . 1. to what common temperature should the ring and the shaft be heated so that the ring will just fit onto the shaft? coefficients of linear thermal expansion of steel and aluminum are 12×10−6 k−1 and23×10−6 k−1 respectively.

What do we mean by the event horizon of a black hole?