Jack wants to know if it takes longer for warm water to freeze into ice cubes than cold water, so he performed the following experiment. jack placed 50 ml of water in the refrigerator and allowed it to cool to a temperature of 4°c. then, he heated 50 ml of water to a temperature of 40°c. jack then used a pipette to distribute 5 ml of cold water into each well of an ice cube tray. he repeated this procedure with the warm water. then, he placed both ice cube trays side by side in a freezer and monitored how long it took for the cubes to freeze. what is the outcome variable (dependent variable) in jack's experiment?