Which rule(s) is used for combining velocities? A. Scalar rules

B. Vector rules

C. Equilibrium rule

The boy of mass 30 kg is at r1= 2 meters from the fulcrum. of the girl is 45 kg, at what r2 must she sit so that they are balanced ?

Acar traveling at 22 m/s starts to decelerate steadily. it comes to a complete stop in 15 seconds. what is it’s acceleration?

Scientists follow specific processes in order to determine valid explanations and conclusions from observations. david observed strange lights in the sky above his home outside of roswell, new mexico. the only explanation that makes sense to him is that there are ufos in the area. what should david do next to verify his explanation?