Answer:
22.5kg
Step-by-step explanation:
Since we not told wat to find, we can as well find the mass of the beaver.
Kinetic energy formula is expressed as;
KE = 1/2mv²
m is the mass
v is the speed
Given
KE = 45Joules
v = 2.0m/s
Substitute into the formula and get the mass
45 = 1/2m(2)²
45 = 2m
m =45/2
m = 22.5kg
Hence the mass of the beaver is 22.5kg