Question

Which of the following would have more momentum than fiona, a 313kg hippo, running at 8m/s?

Answer 1

Let's calculate the momentum of Fiona, given by the product between its mass and its speed:
$p=mv=(313 kg)(8 m/s)=2504 kg m/s$

Now let's compare it with the momentum of the other animals:
a) the mass of the sea turtle is missing, so we cannot calculate its momentum.
b) the momentum of the dolphin is 
$p=mv=(150 kg)(18 m/s)=2700 kg m/s$
c) the momentum of the horse is
$p=mv=(380 kg)(4 m/s)=1520 kg m/s$
d) the momentum of the lion is
$p=mv=(190 kg)(11 m/s)=2090 m/s$

And we can see that the correct answer is b), because the momentum of the dolphin is greater than the momentum of Fiona.