40. A large bear skids to a stop at the top of a cliff with a 90 meter drop. If he has a gravitational potential energy of 55000 Joules at the top of the cliff, what is his mass?

To find the mass of the bear, we can use the formula for gravitational potential energy, which is given by: \[ PE = mgh \] Where: - \( PE \) is the potential energy (55000 Joules) - \( m \) is the mass (what we want to find) - \( g \) is the acceleration due to gravity (approximately \( 9.81 \, \text{m/s}^2 \)) - \( h \) is the height (90 meters) Rearranging the formula to solve for mass (\( m \)) gives us: \[ m = \frac{PE}{gh} \] Substituting in the values: \[ m = \frac{55000}{9.81 \times 90} \] Calculating this gives: \[ m = \frac{55000}{882.9} \approx 62.2 \, \text{kg} \] So, the mass of the bear is approximately **62.2 kilograms**.