Comets travel around the sun in elliptical orbits with large eccentricities. If a comet has speed 2.0×10^4m/s when at a distance of 2.5×10^11m from the center of the sun, what is its speed when at a distance of 5.0×10^10?

The density of gold is 19.3g/cm3. what is the volume of a 13 g gold nugget? ( density: d= m/v)

An object is 10. cm from the mirror, its height is 3.0 cm, and the focal length is 2.0 cm. what is the image height? (indicate the object orientation by including the + or - sign with the answer.) hi = cm +1.33 -1.33 +0.75 -0.75

The charge on an electron is 1.60218 × 10−19 c and its mass is 9.10939 × 10−31 kg. how strong a magnetic field must be experienced by the electron if its path is a circle of radius 5.5 cm? answer in units of t.