Question

You slide a hockey puck across the ice in a hockey rink. The puck gradually slows down as it moves. How does Newton's first law explain the motion of the puck?

Answer 1

@Vocaloid @Shadow @sillybilly123 @Nnesha

Answer 2

Salient Part of Newton's 1st Law:
"An object in motion tends to remain in motion UNLESS acted on by an external force" {emphasis on UNLESS}

In the case of a puck sliding across the ice: it slows (decelerates) because of the friction force between ice and puck. THIS friction force IS the external force spoken about in the 1st Law, above...and...thus is the reason the puck eventually stops moving.