Is velocity positive or negative when acceleration is fast-slow-fast. i need with position time graphs and velocity time graphs

Crowbar of 5 metre is used to lift an object of 800 metre if the effort arm is 200cm calculate the force applied

(a) calculate the number of electrons in a small, electrically neutral silver pin that has a mass of 10.0 g. silver has 47 electrons per atom, and its molar mass is 107.87 g/mol. (b) imagine adding electrons to the pin until the negative charge has the very large value 1.00 mc. how many electrons are added for every 109 electrons already present

The ability to make things happen is also called a. heat b. force c. matter d. energy