At the start of his race, an 81-kg runner pushes against the starting block, exerting an average force of 1600 n . the force that the block exerts on his foot points 20∘ above the horizontal. determine the horizontal speed of the runner after the force is exerted for 0.28 s.

In a voltaic cell, electrons flow from the (positive/negative) to the (positive/negative) terminal.

Which of the following situations is impossible? a) an object has velocity directed east and acceleration directed east. b) an object has zero velocity but non-zero acceleration. c) an object has constant non-zero velocity and changing acceleration. d) an object has velocity directed east and acceleration directed west. e) an object has constant non-zero acceleration and changing velocity.

When is a current produced? when the terminals of an electrochemical cell are connected by a wire if the electric circuit is opened in an electrochemical cell if the electrolyte is removed from an electrochemical cell when the electrodes are reversed in an electrochemical cell