You hold a metal block of mass 40 kg above your head at a height of 2 m.
how much work is done by gravity if you let the block fall to the ground?
o a. -80 j
o b. 80
o c. 784 j
o d. -784

Which of the following is an example of units for speed

Afrequency generator sends a 550 hz sound wave through both water and ice. what is the difference in wavelength between the wave produced in ice and the wave produced in water?

Consider a uniformly charged ring in the xy plane, centered at the origin. the ring has radius a and positive charge qdistributed evenly along its circumference. a)what is the direction of the electric field at any point on the z axis? . b)what is the magnitude of the electric field along the positive z axis? use k in your answer, where k=14πϵ0. d)the ball will oscillate along the z axis between z=d and z=−d in simple harmonic motion. what will be the angular frequency ω of these oscillations? use the approximation d≪a to simplify your calculation; that is, assume that d2+a2≈a2. express your answer in terms of given charges, dimensions, and constants