Aparticle of mass m is placed at the centre of a uniform spherical shell of mass 2m and radius r. the gravitational potential on the surface of the shell is 3 gm

The diagram shows the positions of the sun, moon and earth during spring tides, when the high tides are at their highest and low tides at their lowest. what is it about these positions that causes these high and low tides?

What's erosion? a. the breakdown of rock into smaller pieces b. the removal of weathered products from rock c. a change in rock resulting from exposure to water d. a chemical change in rock that weakens it

Why is the indus river so important to the people of pakistan?