An element's atomic number is 55. how many protons would an atom of this element have?

What object a collides with object b and bounces back its final momentum is?

A100 kg running back runs at 5m/s into a stationary linebacker. it takes 0.5 for the running back to be completely stopped

For this car, predict the shape of a graph that shows distance (x) versus time (t). note that time is the independent variable and will be on the bottom axis. need asap