Answer: 0.66 g/mL
Explanation: The formula for density is d= m/v where m=mass and v=volume.
The mass was given in the problem, m= 1.32kg
The volume was also given in the problem, v= 2.0L
d= m/v ---> d= 1.32kg/2.0L ---> d=0.66kg/L
The problem calls for the answer to be written in g/mL, so we must convert the units. 1 kg contains 1000g and 1 L contains 1000 mL.
1000g/1000mL = 1 so the units change but the 0.66 does not. Therefore, your answer is 0.66g/mL (Two significant figures because 2.0 only has 2 significant figures).
Option B is correct. Average speed can be found through the equation speed = distance/time. Applying this to each person using the data in the chart:
Dennis’ speed: 60 ft/0.5 secs = 120 ft per sec
Johnny’s speed: 60 ft/0.45 secs = 133.333 ft per sec
Travis’ speed: 60 ft/0.52 secs = 115.38 ft per sec
Michael’s speed: 60 ft/0.48 secs = 125 ft per sec
As you can see, Johnny’s speed is the fastest at 133.333 ft/sec.