What happens to the mass number and the atomic number of the original radioactive unstable element when it undergoes beta decay

Alfred pushes on a heavy box, but cannot move it. the box has a lot of inertia motion friction gravity

Anybody wanna ? (picture included? )

Mutt and jeff are running along a path each pushing a cart loaded with rocks. if mutt's wagon has a mass two times greater than jeff's and they want to stay together, arriving at their destination at the same time, what must happen? a) jeff should slow down so mutt can catch up. b) mutt must use half as much force to push his cart. c) mutt must use twice as much force to push his cart. d) mutt and jeff will use the same force, but mutt will take bigger steps.