Questão sobre conservação da energia mecânica Na figura a seguir um bloco de massa 1,0 kg comprime em 10 cm uma mola cuja constante elástica é k =2000 N/m. Soltando-se o sistema mola-bloco, o bloco percorre a trajetória até atingir a altura de 0,60 m em relação ao nível inicial. Adotando g=10 m/s2, determine a energia dissipada ao longo da trajetória.

i am pretty sure it is c because when people are closer together, they cannot move as freely. picture being in a mostly full elevator, for instance. the people are right next to you, and you can barely move.

the box does not move because you need to use a force greater than 300 n. you are only using 50 n. it needs to at least be 301 n for the box to move because then it is an unbalanced force and it will move the way that the greater force is pushing it. if you use only 300 n it will be a balanced force and will not move because the force you are exerting on the   box is the same as its force.

hope this !

im sorry if i went too in depth, i am going to include a link to a video on khan academy that will explain this.   hope that you like the video and that it explains more in detail to you.

that is the link.

dang that balls went far