Q1. A metal sphere has a charge of +8.9x10^-6C. What is the net charge after 8.8 x 10^13 electrons have been located on it?
Q2. A helium-neon laser emits light of wavelength 633 nanometers (nm). Light from an argon laser has the wavelength of 515 nm. Which laser emits the higher-frequency light?
Q3. An astronaut on the Mars attaches a small brass ball to a 1.00- length of string and makes a simple pendulum. She times 13 complete swings in a time of 35.4 seconds. From this measurement she calculates the acceleration due to gravity on the Mars.