1. Work of at least 2000J is required to push a crate up a frictionless incline. If the crate is pushed 20m on the incline and the crate is 20 kg then what is the slope of the incline?
A) 45° B) 90° C) 60° D)30°
2. The kinetic energy of a spring is 100J when compressed by 10cm. What is its spring constant?
A) 10N/cm B) 20 J/cm C) 20000 N/m D) 2000 N/m
3. A plastic cylinder has 20 cm of 750 kg/m 3 oil on top of30 cm of water. Assuming the mass of the plastic cylinder is in important, how high is the center of mass of this container of fluid.
A) 16.66 cm B) 23.33cm C) 30 cm D) 31.67cm