Answer:
As per the statement:
A 900-kg giraffe runs across a field at a rate of 50 km/hr.
⇒ m = 900 kg and

Use conversion:


The magnitude of its momentum is given by:

where
m is the mass in kg
v is the speed in m/s
Substitute the given value we have;

Therefore, the magnitude of its momentum is 12500 kg m/s