Which of these are not mechanical waves and can be used to send a signal to astronauts on the moon?

a) sound waves
b) radio waves
c) both sound waves and radio waves
d) neither sound waves or radio waves

The magnetic field inside a superconducting solenoid is 4.50 t. the solenoid has an inner diameter of 6.20 cm and a length of 26.0 cm. determine (a) the magnetic energy density in the field and (b) the energy stored in the magnetic field within the solenoid.

5g of ammonium nitrate was dissolved in 60g of water in an insulated container. the temperature at the start of the reaction was 23.0°c and at the end it was 19.0°c. calculate the energy absorbed by the reaction.

Positrons are spontaneously emitted from the nuclei of