An object has a relativistic momentum that is 7.1 times greater than its classical momentum. what is its speed? express the answer using two significant figures.

The relativistic momentum of an object is given by

where
is the relativistic factor
is the rest mass of the object
v is the speed of the object
c is the speed of light

The classical momentum is given by


The problem says that the ratio between the relativistic and classical momentum of the object is 7.1, so

Therefore, , and we can use the definition of  to find the object's speed:

Solving, 

And by using , we find the velocity of the object: