It'd be A. Picture one shows a chemical change. Rust is made from the iron reacting with oxygen.
Answer:
d = 19.92 m
Explanation:
As in this exercise there is friction we must use the relationship between work and energy
W = ΔEm
Look for energy in two points
Initial. Fully compressed spring
Em₀ = = ½ k x²
Final. When the block stopped
= 0
Let's look for the work of the rubbing force
W = fr d cos θ
Since rubbing is always contrary to movement, θ = 180
W = - fr d
Let's use Newton's second Law, to find the force of friction
Y Axis
N- w = 0
N = mg
The equation for the force of friction is
fr = μ N
fr = μ mg
We substitute in the work equation
W = - μ m g d
We write the relationship of work and energy
-μ m g d = 0 - ½ k x²
d = ½ k x² / μ m g
Let's calculate
d = ½ 131 2.1 2 / (0.74 2 9.8)
d = 19.92 m
Work=applied Force x distance
= 1275 x 26
=33150 Joules
Answer:
The acceleration is 5 m/s2.
Explanation:
We calculate the acceleration, with the data of mass and force, through the formula:
F= m x a ---> a= F/m
a= 200 N/40 kg 1N= 1 kg x m/s2
a= 200 kg x m/s2/ 40 kg
<em>a= 5 m/s2</em>