Which of the following objects is in mechanical equilibrium, so that Newton’s first law is valid? Mark all that apply.
A. A speed skater accelerating toward his top velocity.
B. A bird caught in an updraft, ascending at a steady rate.
C. An apple falling freely (ignoring air resistance)
D. A dime placed on the dashboard of a car moving at 65 mph down a completely straight stretch of highway.
E. A car held at rest on the ramp of a car-transporter trailer.

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