Understanding the Concepts

* Kinetic Energy: The energy an object possesses due to its motion. It's calculated using the formula: KE = (1/2) * m * v²

* KE = Kinetic energy (in Joules)

* m = mass (in kilograms)

* v = velocity (in meters per second)

Solving the Problem

1. Rearrange the kinetic energy formula to solve for velocity:

v² = (2 * KE) / m

2. Plug in the given values:

v² = (2 * 810 J) / 20 kg

3. Calculate:

v² = 81 m²/s²

4. Take the square root of both sides to find the velocity:

v = √81 m²/s² = 9 m/s

Therefore, the object's speed is 9 meters per second.