(1) A block of mass 800g is pulled from rest on a horizontal frictionless bench by a steady force of F and it travels 16m in 2
seconds. Find:
(a) The acceleration?
(b) The value of F?

a) 8m.

b) 6.4N

Explanation:

a)Using

s=16

u=0

t=2

a=?

16=1/2a(4)

a=8m.

b) F=ma

Where m is in kg

Convert 800g to kg

800/1000=0.8kg (1000g in a kg)

F= 0.8 x 8 = 6.4N

if the thermos has a vacuum innner, then heat through conv currents and conduction are reduced = vacuum flask

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.