Answer:
20 kg
Step-by-step explanation:
The kinetic energy (KE) of an object is given by:
KE = (1/2) * m * v^2
Where m is the mass of the object, and v is its velocity.
We can rearrange this formula to solve for the mass:
m = 2 * KE / v^2
Plugging in the values given:
m = 2 * 1000 J / (10 m/s)^2
m = 20 kg
Therefore, the mass of the Puffin flying at 10 m/s with 1000 J of KE is 20 kg.