If the stone is thrown up vertically and return to the ground, its potential energy is maximum
a) During the upward journey
b) At the maximum height
c) During the return journey
d) At the bottom

The brightest star in the night sky in the northern hemisphere is sirius. its distance from earth is estimated to be 8.7 light years. a light year is the distance light travels in one year. light travels at a speed of 3.00 × 108 m/s. calculate the distance from earth to sirius in miles. (1 mi = 5280 ft) g