What must be the initial velocity of a silver (Ag) bullet at a temperature of 20oC so that the heat developed when it is brought to a complete stop shall be sufficient to bring it to melting point? (Melting point of Silver is 962oC, CAg =240J/kgoC) 672 m/s=2420 km/h

work: w = fd (given)

work done by chet   =50*1 = 50 j

work done by mika =40*2 = 80 j

work done by sara =30*1.5 = 45 j

work done by bill =60*0.5 = 30 j

students in order from the greatest amount of work done to the least is mika> chet> sara> bill

hence option (b) is correct.

iron would move it is magnetic there is a mag field around the current in the wire

if the person is shown to have +90n, then ans is -10n.

if the person is shown to have -90n, then ans is +10n.