Two people are pulling the same 12 kg box along a flat, frictionless surface. One pulls up and to the right with a 30 N force at 20°, the second pulls up and to the left
with a 45 N force at 50°. What is the acceleration of the box?
3.00 m/s^2
09.80 m/s^2
O 1.474 m/s^2
0.474 m/s^2

The acceleration is 0.062 m/s^2.

Explanation:

mass = 12 kg

F = 30 N at 20° right

F' = 45 N at 50° left

Let the acceleration is a.

The net force is

F'' = F' cos 50° - F cos 20°

F'' = 45 x 0.643 - 30 x 0.94 = 28.94 - 28.2 = 0.74 N

According to the Newton's second law

0.74  = 12 x a

a = 0.062 m/s^2

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

unlike poles attract