Answer:
F = 24 N
Explanation:
In this exercise we have a bar l = 100 m with a center of gravity x = 4 m, which force is needed to lift it from the other end
Let's use the rotational equilibrium relationship, where we consider the counterclockwise rotations as positive and fix the reference system at the point closest to the center of gravity
∑ τ = 0
F l -x W = 0
F = 
let's calculate
F =
4/100 600
F = 24 N
The volume of a cube is given by:

where L is the measure of each side (which corresponds to its width, since all sides of a cube are equal).
Plugging the data of the problem, L=32.1 cm, inside the equation, we find the volume:

Answer:
Question 1 the answer is 5 cm for the one pulley system, I just took the quiz
Question 2 is 10 cm
Explanation:
The rope only needs to move 5 cm for the mass to move from 15 to 20.
For the 2 pulley system the string has to move twice as far making it 10 cm. I took the quiz and got 100%
Answer: colder and drier
Explanation:
Trees don’t grow well in wet climates, nor when they are cold. The wider the rings, the healthier the tree is. Since it was narrow and then wide, was bad climate and then good.