Aturntable with a radius of 8cm rotates at 45 rpm. what is the linear speed of a point on the outside rim?

Assuming the turntable is circular, its circumference is

(2 π) x (its radius) .

That's the distance covered by a point on its rim during every complete revolution.

The distance covered by the same point during 45 revolutions is

(45) x (2 π) x (radius).

So we can write . . .

Speed of the point = (45 rev/min) · (2 · π · 8 cm / rev)

Speed = (720 π)  cm/minute

Speed = 12π  cm/second

Speed = 37.7 cm/sec

Speed = 0.377 m/s

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.