Hand-cranked flashlights transform mechanical energy into other forms of energy. Which energy transformations are useful, and which are not? Explain why most hand-cranked flashlights are made with LEDs

What is the energy of a photon of ultraviolet radiation with a frequency of 4.4 × 1015 hz? planck’s constant is 6.63 × 10–34

You throw a baseball directly upward at time =0 at an initial speed of 14.9 m/s. what is the maximum height the ball reaches above where it leaves your hand? ignore air resistance and take =9.80 m/s2.

Adisk with a radius of r is oriented with its normal unit vector at an angle q with respect to a uniform electric field. which of the following would result in an increase in the electric flux through the disk? check all that apply? a. increasing the area of the disk b. decreasing the given orientation angle of the disk c. decreasing the strength of the electric field d. increasing the given orientation angle of the disk, but not exceeding an angle of 90