How can we protect ourselves from ultraviolet radiation

Aturntable a is built into a stage for use in a theatrical production. it is observed during a rehearsal that a trunk b starts to slide on the turntable 10 s after the turntable begins to rotate. knowing that the trunk undergoes a constant tangential acceleration of 0.31 m/s2, determine the coefficient of static friction between the trunk and the turntable.

Which subatomic particle has a negative charge

Which is the correct symbol for an isotope of iodine with 53 protons and 78 neutrons?