The gravitational acceleration on the planet Uranus is 8.87 m/s² .
If we proceed with a legitimate response and ignore the possible intent of a crude, sophomoric anatomical reference in the question, the weight of the rock would be
Weight = (mass) x (gravity)
weight = (25 kg) x (8.87 m/s²)
Weight = (25 x 8.87) (kg-m/s²)
Weight = 221.75 Newtons (compared to 245.25 Newtons on Earth)
