What is the rate of change of an object’s velocity per unit of time known as?

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

You notice the birds sitting on the electrical wires which of the following explain why the birds don't get shocked

Suppose that two objects attract each other with a gravitational force of 16 units. if the distance between the two objects is double, what is the new force of attraction between the two objects?