How much potential energy does a 40-n medicine ball gain when it is lifted 5 m?
200 j
1,000 j
100 j
20 j

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.