1. A wave travelling on a string has a wavelength of 0.10 m and a
frequency of 7 Hz. Calculate the speed of the wave

speed = 0.7 m/s

Explanation:

speed = frequency x wavelength

speed = 7Hz x 0.10m

speed = 0.7 m/s

radiation warms things up temp rises convection currents air circ windy weather

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.