A metal frame is pulled out of magnetic field at a constant velocity LaTeX: \small \vec{v}v → by a force LaTeX: \vec{F}_{pull}F → p u l l. The metal frame has resistance R and the changing magnetic flux induces a current LaTeX: ii in the frame. The magnetic field acting on the induced current generates a force LaTeX: \vec{F}_BF → B. Neglect all other forces.

It's a snowy day and you're pulling a friend along a level road on a sled. you've both been taking physics, so she asks what you think the coefficient of friction between the sled and the snow is. you've been walking at a steady 1.5m/s, and the rope pulls up on the sled at a 32 ∘ angle. you estimate that the mass of the sled, with your friend on it, is 65 kg and that you're pulling with a force of 80 n .