Which clue can be used to identify a chemical reaction as a replacement reaction

Keneila is attempting to ski down a 20 m high friction free hill for the first time. she has a speed 10 m/s at the top. what is her kinetic energy when she is a the bottom, 20 m ? (a)2500 j (b)9800 j (c)12300 j (d)3100j (e)15000j

If forces acting on an object are unbalanced. true or false

How much energy is supplied to each coulomb of charge that flows through a 12-v battery?