You could increase the mechanical efficiency of this screw by

adding more threads to the screw

reducing friction along the screw threads

making the screw threads longer

making the inclined plane longer

The consumption of fossil fuels could be

Work out sian speed for the first 30 minutes of her journey. give your answer in km/h.

Which of the following correctly describes what happens when an atomic bomb explodes? small pieces of fissionable material are joined and form a body with a mass greater than the critical mass, the relative number of neutrons escaping decreases, and a chain reaction and explosion result. large pieces of fissionable matter are brought together quickly and form a body with a mass smaller than the critical mass, the relative number of escaping neutrons increases, and a chain reaction and explosion result.