A rock of mass 170 kg needs to be lifted off the ground. One end of a metal bar is slipped under the rock, and a fulcrum is set up under the bar at a point that is 0.65 m from the rock. A worker pushes down (perpendicular) on the other end of the bar, which is 1.9 m away from the fulcrum. What force is required to move the rock?

10. a person with a mass of 15 kg is walking uphill at a velocity of 2 m/s. what is the walker's momentum? a. 15 kg-m/s b. 30 kg-m/s c. 10 kg-m/s d. 13 kg-m/s 16. two bouncy balls colliding with each other is an example of what type of collision? a. inelastic collision b. elastic collision c. parallel collision d. mass collision 20 which of the following is considered to be a vector? a. temperature b. mass c. velocity d. time