Plz tell answer of this

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.

In a good thermo flask the main cause of heat loss is

The earth exerts a gravitational force of 500 n on amy. what is amy’s mass in kg?