Manuel and Sandy were partners. Sandy held the accelerometer in her hands while Manuel watched the water line. Throughout Sandy's walk, the water line remained level. What does that tell the students about Sandy's motion? A) Sandy's velocity changed when she slowed down or sped up.
B) Sandy's speed might have changed but her direction did not.
C) Sandy must not have been moving if the water line remained level.
D) Sandy's velocity is constant; her speed and direction did not change.

Achemist at a pharmaceutical company is measuring equilibrium constants for reactions in which drug candidate molecules bind to a protein involved in cancer. the drug molecules bind the protein in a 1: 1 ratio to form a drug-protein complex. the protein concentration in aqueous solution at 25 ˚c is 1.74 x10-6 m . drug a is introduced into the protein solution at an initial concentration of 2.00 x10-6m. drug b is introduced into a separate, identical protein solution at an initial concentration of 2.00 x10-6m. at equilibrium, the drug a-protein solution has an a-protein complex concentration of 1.00 x10-6m, and the drug b solution has a b-protein complex concentration of 1.40 x10-6m. a. calculate the kc value for the a-protein binding reaction. b. calculate the kc value for the b-protein binding reaction. c. assuming that the drug that binds more strongly will be more effective, which drug is the better choice for further research?