Witch of these best describes how a powerful electromagnets could be used in a junkyard?

Joan writes four numbers on the board in standard form, and then she writes their scientific notation

Displacement is the slope of a velocity vs. time graph a. true b. false

100 grams of molten lead (600°c) is used to make musket balls. if the lead shot is allowed to cool to room temperature (21°c), what is the change in entropy (in j/k) of the lead? (for the specific heat of molten and solid lead use 1.29 j/g⋅°c; the latent heat of fusion and the melting point of lead are 2.45 × 104 j/kg and 327°c, respectively.)