2.5 kg because you cant change the weight of the rock
-0 m/s
- average velocity=displacement/time
- the runners displacement is zero so her average velocity must be zero
The First Law describes how an object acts when no force is acting upon it. So, rockets stay still until a force is applied to move them. Likewise, once they're in motion, they won't stop until a force is applied. Newton's Second Law tells us that the more mass an object has, the more force is needed to move it. A larger rocket will need stronger forces (eg. more fuel) to make it accelerate. The space shuttles required seven pounds of fuel for every pound of payload they carry. Newton's Third Law states that "every action has an equal and opposite reaction". In a rocket, burning fuel creates a push on the front of the rocket pushing it forward.
Answer:External forces are forces caused by external agent outside of the system. Internal forces are forces exchanged by the objects in the system.
Explanation:or our purposes, we will simply say that external forces include the applied force, normal force, tension force, friction force, and air resistance force. And for our purposes, the internal forces include the gravity forces, magnetic force, electrical force, and spring force.HOPE THIS HELPS!!! ^w^
