Ultrasound was used to check for cracks in an aeroplane wing. The ultrasound pulse would be reflected from any cracks and from the end of the wing. The diagram shows the oscilloscope trace produced by the echo. How far along the wing was the crack? The speed of sound in metal is 5000 M/S.

Red light strikes a metal surface and electrons are ejected. if violet light is now used with a 10% greater intensity, what will happen to the ejection rate (number of ejected electrons per second) and the maximum energy of the electrons? a) greater ejection rate; same maximum energyb) same ejection rate; greater maximum energyc) greater ejection rate; greater maximum energyd) same ejection rate; same maximum energye) none of the above answers are correct

Which of the following are forms of phase changes a. freezing b. condensation c. heating d. exchanging

Which statements best describe energy? check all that apply. the total amount of energy in the universe remains constant. the total amount of energy in the universe changes constantly. energy cannot be converted from one form to another. energy can be converted from one form to another. energy cannot be created or destroyed. energy can be created or destroyed.