Given:
Velocity = 80 m/s
Momentum = 850 kg.m/s
Let's find the mass of the body.
Apply the formula:

Where:
p is the momentum
m is the mass
v is the velocity.
Rewrite the formula for mass, m

Thus, we have:

The mass of the body is 10.625 kg.
ANSWER:
1.) 10.625 kg