To apply a new waterproofing membrane on top of an old bitumen waterproofing membrane, the surface of the old membrane should be thoroughly cleaned and prepared. Any loose debris, dirt, or old adhesive should be removed to ensure proper adhesion of the new membrane. Once the surface is clean, a primer should be applied to promote adhesion between the old and new membranes. Finally, the new waterproofing membrane can be installed according to the manufacturer's instructions, ensuring that it is properly sealed and bonded to the old membrane to provide effective waterproofing. **

Nike Air Force shoes are not waterproof, but they are water-resistant to some extent. The materials used in the construction of the shoes provide some protection against light rain and splashes. However, they are not designed to be fully waterproof and may not provide adequate protection in heavy rain or wet conditions. It is always recommended to use a waterproofing spray or treatment to enhance the water resistance of the shoes. **

A utility knife or a sharp blade is typically used to cut the waterproofing membrane. It is important to use a sharp tool to ensure clean and precise cuts, which will help in achieving a proper seal and prevent water leakage. Care should be taken to avoid damaging the underlying surface while cutting the membrane. **

Ideally, the waterproofing membrane should be applied in dry weather to ensure proper adhesion and effectiveness. If the membrane is applied and then it rains before it has fully cured, it can compromise its ability to create a watertight seal. Water exposure during the curing process can lead to delamination, reduced adhesion, and potential leaks. Therefore, it is best to apply the waterproofing membrane when there is no rain in the forecast and allow it to fully cure before any water exposure. **

Centrifugal force is considered a fictitious force because it only appears to act on objects in a rotating reference frame, such as a spinning carousel or a turning car. In reality, the object is moving in a straight line, but it appears to be pushed away from the center of rotation due to inertia. On the other hand, centripetal force is a real force that acts towards the center of rotation, keeping an object moving in a circular path. This force is necessary to maintain the object's curved motion and prevent it from moving in a straight line. **

The force of gravity is the fundamental force that governs the motion of objects in the universe. It is responsible for keeping planets in orbit around the sun, causing objects to fall to the ground, and creating tides on Earth. Gravity is a universal force that acts between all objects with mass, and its strength depends on the mass of the objects and the distance between them. **

Centrifugal force is considered a fictitious force because it only appears to act on objects in a rotating reference frame, such as a spinning carousel or a turning car. In reality, the object is moving in a straight line, but it appears to be pushed away from the center due to the rotation. On the other hand, centripetal force is a real force that acts towards the center of rotation, keeping an object moving in a circular path. This force is necessary to maintain the object's curved motion and prevent it from moving in a straight line. **

The centripetal force is responsible for keeping an object moving in a circular path. This force is provided by another force acting towards the center of the circle, such as tension in a string, gravitational force, or friction. Without this centripetal force, the object would move in a straight line tangent to the circle. **