James gently releases a ball at the top of a slope, but does not push the ball. the ball rolls down the slope. which force caused the ball to move downhill?

The ball moved downhill due to the gravitational force.

When the ball is at the top of the downhill the gravitational force is more than the frictional force, this makes the ball come down without pushing it. Gravitational force is the universal force is applicable to all the objects on the earth. The force by which one object attracts other objects. Due to this gravitational force the ball rolls down to ground from downhill without any push.

one part of the electromagnetic spectrum that arrives on earth as solar radiation from the sun is the visible spectrum. wavelengths of the visible spectrum combine to form what we refer to as

answer - d) ultraviolet radiation.

violet /   380–450 nm / 668–789 thz

violet is number 1 in the chart of visible light.