What is the average speed of a vehicle that covers 250 miles in two-and-a-half hours?

An airplane flying parallel to the ground undergoes two consecutive displacements. the first is 76 km at 39.8◦ west of north, and the second is 156 km at 59.9◦ east of north. what is the magnitude of the plane’s total displacement? answer in units of km. 020 (part 2 of 2) 10.0

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

Can anybody me with this? ? (picture included.)