A 9 N horizontal force is needed to keep an object that weighs 4 N moving at a constant speed. What is the magnitude of the frictional force acting on the object?
A straight segment of wire 35.0 cm long carrying a current of 1.40 A is in a uniform magnetic field. The segment makes an angle of 53∘ with the direction of the magnetic field.
If the force on the segment is 0.200 N, what is the magnitude of the magnetic field?