What is that product of an objects mass and velocity

Find v(t), given acceleration a(t)=7j and initial velocity v(0)=k

The pressure proportional to the area a- inversely b- directly c- increase d-decrease

There are two-speed cameras, one in an are where the speed limit is 30 km/h and another where the speed limit is 50 km/h. in which will there be a smaller time interval between the photographs? explain your answer.