Em uma final de campeonato um jogador cruza a bola de massa 0,5 Kg para o seu colega de time que está na área adversária (figura abaixo). A bola sai do chão com uma velocidade de 10 m/s e vai direto para cabeça do atacante (ponto p) que dista 2 m do chão. Desconsiderando qualquer tipo de atrito, a energia cinética da bola no ponto p é: a) - 10 J
b) 8 J
c) 15 J
d) 10 J

Follow these directions and answer the questions. 1. set up the ripple tank as in previous investigations. 2. bend the rubber tube to form a "concave mirror" and place in the ripple tank. the water level must be below the top of the hose. 3. generate a few straight pulses with the dowel and observe the reflected waves. do the waves focus (come together) upon reflection? can you locate the place where the waves meet? 4. touch the water surface where the waves converged. what happens to the reflected wave? 5. move your finger twice that distance from the hose (2f = c of c, center of the curvature) and touch the water again. does the image (the reflected wave) appear in the same location (c of c)? you may have to experiment before you find the exact location. sometimes it is hard to visualize with the ripple tank because the waves move so quickly. likewise, it is impossible to "see" light waves because they have such small wavelengths and move at the speed of light. however, both are examples of transverse waves and behave in the same way when a parallel wave fronts hit a curved surface.

The magnitude of the poynting vector of a planar electromagnetic wave has an average value of 0.939 w/m^2 . the wave is incident upon a rectangular area, 1.5 m by 2.0 m, at right angles. how much total electromagnetic energy falls on the area during 1.0 minute?

Wavelength of 125 meters is moving at a speed of 10 m/s. what is it's frequency?