Henry is measuring a metal cylinder with a spring scale. About how much does the cylinder weigh? A. 2 N B. 12 N C. 10 N D. 20 N

What color of light must blue light mix with to create white light? a. yellow b. white c. blue d. green

At 20∘c, the hole in an aluminum ring is 2.800 cm in diameter. you need to slip this ring over a steel shaft that has a room-temperature diameter of 2.804 cm . 1. to what common temperature should the ring and the shaft be heated so that the ring will just fit onto the shaft? coefficients of linear thermal expansion of steel and aluminum are 12×10−6 k−1 and23×10−6 k−1 respectively.

Awave has a wavelength of 7 mm and a frequency of 19 hertz. what is its speed?