How Do You Calculate the Mass of a Blue Whale Using Momentum?

[danield3]

1. The blue whale is the largest mammal ever to inhabit Earth. Calculate the mass of a female blue whale if, when alarmed, it swims at a velocity of 57.0 km/h [E] and has a momentum of 2.15*10^6 kgm/s [E].

mass=momentum/velocity = 2.15x10^6kgm/s / 15.8m/s

mass=1.36x10^5kg2. Use reasoning to determine if one of the following objects in each of these pairs has a greater value for the magnitude of its momentum than the other. (No calculations should be required.)

a. a 900.0-kg truck traveling at 60 km/hr, or a 500.0-kg car traveling at 60 km/hr
900.0 kg

b. a 15.0-kg object traveling to the right at 5.0 m/s, or a 15.0-kg object traveling to the left at 5.0 m/s

both
c. a 900-kg truck at rest, or a 500-kg car at rest
900 kg

d. a 900-kg truck at rest, or a mosquito flying at 2 m/s

Mosquito

 

[The legend]

Your approach to the first one looks right..(havent checked calculations)

ummm... how have you approached the 2nd question?