A spaceship takes a straight line path from the earth to the moon, a distance of about 400000 km. Suppose it accelerates at 5 m/s2
for the first 10 min of the trip, then travels at constant speed until the
last 10 min, when it accelerates at – 5 m/s2
, just coming to rest as it reaches the moon (a) What is the
maximum speed attained? (b) What total time required for the trip?

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.

force required to detach it is given by

charges are taken to be fundamental charge

now we have

so above is the minimum distance at which it will detach

according to jean piaget, in what stage of cognitive development are children able to understand conservation task?

b. preoperational

just took it