The density of aluminum is 16.4 grams per cm^3 what is the mass of 128.5 gallons of aluminum

Question

The density of aluminum is 16.4 grams per cm^3 what is the mass of 128.5 gallons of aluminum

 

And 

 If a car is accelerating at a speed of 3.0m/s how will it take starting from rest to exceed the speed limit 55mi/hr

Answer 1

16.4 g/cm³ = 16.4 kg/Liter

1 liter = 0.264172 gallons

 

128.5 gallons Al x 1 liter/0.264172 gallons x 16.4 kg/liter = 7977 kg = mass of Al

 

1 m/sec = 2.23694 miles/hour

3.0 m/sec = 6.71 miles/hour

(6.71 miles/hour) (x hours) = 55 miles/hour

x = 8.197 hours = 8.2 hours