Starting from rest, a 2.1x10^-4 kg flea springs straight upward. while the flea is pushing off from the ground, the ground exerts an average upward force of 0.41 n on it. this force does 3.7x10^-4 j of work on the flea.
(a) what is the flea's speed when it leaves the ground?
(b) how far upward does the flea move while it is pushing off? ignore both air resistance and the flea's weight.

Electromagnetic induction. a coil of wire contains n turns and has an electrical resistance r. the radius of each turn is a. initially, inside the coil there exists a uniform magnetic field of magnitude b0 parallel to the axis of the coil. the magnetic field is then reduced slowly. the current induced in the coil is i. how long does it take for the magnitude of the uniform field to drop to zero?

In this thread, i would like you to comment on the nature of light and how operation of telescopes. light has a duality of a particle and a wave; which one affects your life? also how does light interact with optics inside telescopic systems? answer these questions in two paragraphs. then respond the another students response.

Which of the following is a characteristic shared by both electron and light microscopes? a. they both employ the use of objective lenses. b. both microscopes require an internal camera to visualize the specimen. c. both microscopes have a resolving power of 0.01 nm. d. they both utilize white light to magnify the specimen.