A uniform rod 1 m long has weights of 20 N and 8 N hanging from its ends. If it balances on a knife-edge at 30 cm from one end, what is the weight of the rod?

How much force must a locomotive exert on a 12840-kg boxcar to make it accelerate forward at 0.490 m/s2?

Which best represents the law of conservation of mass ?

You are given a vector a = 125i and an unknown vector b that is perpendicular to a. the cross-product of these two vectors is a × b = 98k. what is the y-component of vector b?