What is the momentum of a helicopter of mass 200 kg moving with a speed of 3 m/s?

What are chlorofluorocarbons and what impact do they have on the atmosphere?

Why does the equilibrium position of the spring change when a mass is added to the spring? will the mass oscillate around the new equilibrium position of the spring or the previous position without a mass attached to the spring? if the equilibrium position of the spring changes by 20 cm (assuming no initial mass) when a mass is added to the spring with constant 4.9 kg/s^2, what is the mass of the object attached to the spring?

Are good conductors of heat also good conductors of electricity? explain your answer.