An oscillator makes four vibrations in one second. what is its period and frequency

What type of electromagnetic wave is used in security pens? a. x-rays c. microwaves b. visible light d. ultraviolet radiation select the best answer from the choices provided

According to newton's second law, when the same force is applied to two objects of different masses, a the object with greater mass will experience a great acceleration, and the object with less mass will experience an even greater acceleration, b. the object with greater mass will experience a smaller acceleration, and the object with less mass will experience a greater acceleration, c. the object with greater mass will experience a greater acceleration, and the object with less mass will experience a smaller acceleration, d. the object with greater mass will experience a small acceleration, and the object with less mass will experience an even smaller acceleration.

Which type of wave can travel without a medium