How does collecting petroleum affect the environment?

Given the position vector of the particle r(t)=(t+1)i+(t^2−1)j+2t k, find the particle's velocity and acceleration vectors at t=1

The charge on a charged sphere is: a)concentrated at its centerb)distributed uniformly throughout its volumec)clustered on its centerd)distributed uniformly over its surface

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.