Complete question:
A 200 g load attached to a horizontal spring moves in simple harmonic motion with a period of 0.410 s. The total mechanical energy of the spring–load system is 2.00 J. Find
(a) the force constant of the spring and (b) the amplitude of the motion.
Answer:
(a) the force constant of the spring = 47 N/m
(b) the amplitude of the motion = 0.292 m
Explanation:
Given;
mass of the spring, m = 200g = 0.2 kg
period of oscillation, T = 0.410 s
total mechanical energy of the spring, E = 2 J
The angular speed is calculated as follows;

(a) the force constant of the spring

(b) the amplitude of the motion
E = ¹/₂kA²
2E = kA²
A² = 2E/k

Since force = mass X acceleration, then the force he excerts on the earth (aka his weight) equals his mass times the force of gravity.
Therefore
W = (66 kg) X (9.8 m/ss)
W = 646.8 kgm/ss
kg m/ss are also known as Newtons, so your answer is...
646.8 N
Answer:
Change in momentum will be -4.4 kgm/sec
So option (A) is correct option
Explanation:
Mass of the ball is given m = 0.10 kg
Initial velocity of ball 
And velocity after rebound 
We have to find the change in momentum
So change in momentum is equal to
( here negative sign shows only direction )
So option (A) will be correct answer
The best answer is b) increased turbidity from erosion.
Nonpoint source pollution generally happens as a result of many systems interacting, and is not directly attributed to one event or pollutant. Generally, natural environmental systems participate in pollution of this kind, regardless of whether or not human activity was a factor. Examples include water runoff, or erosion.
The other pollutants listed have a direct cause and direct effect, the animal waste goes directly from the animals to the ground they live on, the car shop directly sumps the oil on the ground, and the oil tank leaks directly into the earth. Erosion causing turbidity is a less direct form of pollution, and is due to the synthesis of several natural phenomena<span />
Answer:

Explanation:
The original equation is:

We notice that:
- we have 1 atom of Fe on the left, and 2 atoms of Fe on the right
- we have 2 atoms of O on the left, and 3 atoms of O on the right
Therefore, the equation is not balanced.
In order to balance it, we can add:
- a coefficient 3 in front of 
- a coefficient 2 in front of 
So we have:

Now the oxygen is balanced, but the iron it not balanced yet, since we have 1 Fe on the left and 4 on the right. Therefore, we should add a coefficient 4 on the Fe on the left:
