15. Um corpo de pequenas dimensões e de 50 kg de massa encontra-se sobre um plano horizontal liso e desloca-se com velocidade escalar constante e de módulo igual a 10 m/s . Em determinado instante, aplica-se a esse corpo uma força vec F , horizontal e oposta ao movimento que o corpo estava descrevendo, com intensidade igual a 100 N. O corpo somente realiza movimento de translação. Determine, em unidades SI: a) a distância percorrida pelo corpo ao fim de 2,0 s, con tados a partir do instante em que se aplicou a força F; b) o intervalo de tempo gasto para que o corpo pare, con tado a partir do instante em que se aplicou a força vec F . 1

Ten students stand in a circle and are told to make a transverse wave. what best describes the motion of the students? each student bumps the shoulder of his or her neighbor. at the exact time, all students take a step to the right. the students skip clockwise, going in a circular motion. one at a time, each student lifts his or her hands up and then down.

Edward tolman explained the results of his study by theorizing that the rats were learning about the maze during every trial but they a. were agitated because other groups were getting reinforcement b. could not remember how to demonstrate it without reinforcement c. were not motivated to demonstrate it without reinforcement d. seemed to be too lazy to actually work without reinforcement

Glass is transparent to visibile light under normal conditions; however, at extremely high intensities, glass will absorb most of the light incident upon it. this works through a process known as multiphoton absorption. in this process, several photons are absorbed at the same time. if very intense light whose photons carry 2ev of energy is shined onto a material with a band gap of 4ev, that light can be absorbed through two-photon absorption, because two photons have the right amount of energy to bridge the band gap. what is the minimum number of photons of 800-nm light that are needed to equal or exceed the band gap of fused silica glass