Question

1. a 25kg tree limb is 14 m above the ground. during a hurricane, it falls on a roof that is 6m above the ground. find the kinetic energy of the limb when it reaches the roof. assume no air resistance.

Explanation:

Step1: Calculate height fallen

$\Delta h = 14.4\ \text{m} - 6\ \text{m} = 8.4\ \text{m}$

Step2: Convert mass to kg

$m = 25\ \text{kg}$

Step3: Use energy conservation

Kinetic Energy (KE) = Gravitational Potential Energy Lost:
$\text{KE} = mgh$
$\text{KE} = 25\ \text{kg} \times 9.8\ \text{m/s}^2 \times 8.4\ \text{m} = 2082.5\ \text{J}$

Answer:

2082.5 J