Energy cannot be destroyed or created, but energy could be transformed or transferred. For example a skiier skiing from the mouth can have potential energy transferred into kinetic energy.
The efficiency of any machine is given by:
efficiency = output obtained / input given
Substituting the values,
Efficiency = 105 / 150
Efficiency = 0.7
Converting this to a percentage, the efficiency of the hammer is 70%.
This is a fairly high efficiency, and this is due to the fact that the hammer is a simpler machine. The more complex a machine is, the greater are the losses in it due to friction, meaning there is a lower efficiency.
2.) Average atomic mass =Σ (abundance x molar mass) /100
= (12.64 x 302.04 + 18.23 x 304.12 + 69.13 x 305.03) /100
=304.486 u(Dalton) . This is avg atomic mass.
A chemical reaction that releases energy usually in the form of heat
