Please someone helppp

Identical marbles are released from the same height on each of the following four frictionless ramps . compare the speed of the marbles at the end of each ramp. explain your reasoning

Critical mass is the of material required to produce a chain reaction. a.) minimum amount b.) atomic mass c.) precise amount d.) maximum amount

Acertain half-reaction has a standard reduction potential e_red^0 = -0.94 v. an engineer proposes using this half-reaction at the cathode of a galvanic cell that e must provide at least 1.00 v of electrical power. the cell will operate under standard conditions. a. is there a minimum standard reduction potential that the half-reaction used at the anode of this cell can have? b. is there a maximum standard reduction potential that the half-reaction used at the anode of this cell can have?