An astronaut on a distant planet wants to determine its acceleration due to gravity. the astronaut throws a rock straight up with a velocity of +16 m/s and measures a time of 21.2 s before the rock returns to his hand. what is the acceleration (magnitude and direction) due to gravity on this planet? (indicate direction by the sign of the acceleration.)

Neurons are components of the nervous system of the body that transmit signals as electrical impulses travel along their length. these impulses propagate when charge suddenly rushes into and then out of a part of the neutron called an axon. measurements have shown that, during the inflow part of this cycle approximately 5.6x10^11 na per meter, each with a charge of e enter the axon. how many coulombs of charge enter a 1.10 cm length of axon during this process