A boy weight 300n climbs to the top of a hill of height 20m. what is the work done by the boy against the force of gravity

from 1609, galileo galilei used the recently invented telescope to observe the sun, moon and planets. he saw the mountains and craters of the moon, and for the first time revealed the planets to be worlds in their own right. galileo also provided strong observational evidence that planets orbited the sun.

his discoveries about the moon, jupiter's moons, venus, and sunspots supported the idea that the sun - not the earth - was the center of the universe, as was commonly believed at the time.galileo turned his gaze toward venus, the brightest celestial object in the sky - other than the sun and the moon.

muscle endurance

explanation:

i can do 50 in a row ( but i get so tired after that)

3.2x10^7

true tan speed = ang vel x radius