Two cannons sit on top of a 100 m high cliff. they fire identical cannon balls at the exact same moment. cannon ball a is fired at 20 m/s. cannon ball b is fired at 15 m/s. what will cannon ball b's vertical velocity (vx) be after 3 seconds?

The first-order reaction a→2b+c has rate constant 0.538 s−1. if the initial concentration of a is 0.867 mol l−1, what is the half-life of the reaction in seconds? remember to use correct significant figures in your answer (round your answer to the nearest hundredth). do not include units in your response.