Ahockey puck is set in motion across a frozen pond. if ice friction and air resistance are neglected, the forcerequired to keep the puck sliding at constant velocity isa) the weight of the puck divided by the mass of the puck. b) the mass of the puck multiplied by 9.8 meters per second per second.~qual to the weight of the puck.'i.£l/ero newtons. e) none of these.

Zero Newtons

Explanation:

Newton's second law of motion states that the net force applied to an object is equal to the product between the object's mass and its acceleration:

In this case, we want the hockey puck to slide at constant velocity - constant velocity means zero acceleration:

a = 0

And so this means also that the net force is zero:

F = 0

However, the problem says that ice friction and air resistance are negligible - so there are no forces acting on the hockey puck. This means that the puck will continue its motion at constant velocity if we don't apply any other force on it.

what experimental evidence led scientists to change from the previous model to this one?

a few of the positive particles aimed at a gold foil seemed to bounce back.

the colors of light emitted from heated atoms had very specific energies.

experiments with water vapor showed that elements combine in specific proportions.

cathode rays were bent in the same way whenever a magnet was brought near them.

your answer is, orbit around the nucleus