Boredom... I'm just plain stupid... (Don't know which equations to use...) If a 256 kg spacecraft weights 436 newtons when it is on the moon, what is the gravitational field strength (in N/kg) there? To slide a 9.0 kg object at constant speed along the ground requires a force of 14.3 N. What is the coefficient of friction? You are pulling a 50 kg mass over a rough surface of friction coefficient µ = 0.15 and you are pulling the mass using a spring of force constant = 200 N/m. How much would the spring stretch? How much does a 55 kg girl compress the spring in a pogo stick when she stands on it? You are given that the spring constant is 78 N/cm.