1401S 56. Steam at 100°C, is passed into a container of negligible heat capacity, containing
20g of ice and 100g of water at 0°C, until the ice is completely melted. Determine the
total mass of water in the container. [Specific latent heat of steam = 2300Jg
specific latent heat of ice = 340 specific heat capacity of water = 4.2 Jg 'K'l

waves moving from a fast medium to a slow medium will experience a reflection as light travels more slowly than red light. total internal reflection occurs when the critical angle is.

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.