Can anyone please answer/explain this im in the middle of a test

The position of a crate sliding down a ramp is given by x=(0.05t^3) m, y=(1.7t^2) m, z=(6−0.85t^5/2) m, where t is in seconds. (a) determine the magnitude of the crate's velocity when t = 2 s. (b) determine the magnitude of the crate's acceleration when t = 2 s.

Where should a carbon monoxide detector be mounted?

How long will it take a car traveling of a constant speed of 45m/s to cover the distance of a 2.5km?