Julie carries an 8.0-kg suitcase as she walks 18 m along a horizontal walkway to her hotel room at a constant speed of 1.5 m/s. How much work does Julie do in carrying her suitcase?

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.