What is this answer to order - family

What are the three ways that an object can accelerate

Gordon is going for a run through the park, but it is cold outside. the low outside temperature could affect his personal safety.

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.